optoprep combined
Fitting height that is appropriate for a 6 YO with PAL
4 mm higher than normal
What wavelength of light is most readily absorbed by the photopigment rhodopsin? 507 nm 460 nm 555 nm 480 nm
507 nm [555 nm is the peak sensitivity for photopic conditions]
visual evoked potentials (VEPs) have demonstrated that adult levels are actually reached by
6-8 mo but fpcl 20/20 isnt until 3-5 yo.
When do VEP results reach adult age?
6-8mo
Tear volume in a normal, healthy, young adult measures approximately between
6.0 - 8.0 microliters
For hydroxychloroquine, retinopathy can occur with
6.5mg/kg/d or a cumulative dose of greater than 1000g.
What is the minimum thickness necessary for an antireflective coating (n=1.9) to be useful against incident light of 530 nm wavelength? 139.5 nm 58.3 nm 278.9 nm 132.5 nm 69.7 nm
69.7 nm thickness = wavelength/(4 x index of coating)
Degrees of separation on the fan chart?
7.5 deg
Globular v. fibrous proteins
Globular - generally compact, water-soluble, and ball-shaped. Most enzymes are globular. Fibrous - elongated, strong, not water-sol; responsible for structure. Ex - collagen
Which metabolic pathways occur in the brain for the derivation of adenosine triphosphate (ATP)? Proteolysis and beta-oxidation Gluconeogenesis and glycolysis Beta-oxidation and the Krebs cycle Glycolysis and the Krebs cycle Gluconeogensis and proteolysis
Glycolysis and the Krebs cycle
Group 3 contact lenses
Group 3 lenses have low water content (less than 50%) and are fabricated from an ionic polymer.
Group 4 contact lenses
Group 4 lenses possess high water content (greater than 50%) and are made from an ionic polymer. Lenses made from ionic compounds tend to attract more proteins from the tear film; therefore, patients who accumulate deposits more rapidly should be fit into lenses from Group 1. Non-silicone hydrogel soft lenses from this group are associated MOST with protein deposits.
Timeline of lash growth
Grows for 2 months Then falls out after 3-5 mo
which is a gram (-) rod that uses chocolate agar for Dx
H influenzae
ATR corneal cyl will show what FL pattern under a sph CL
H pooling V touch
WTR corneal cyl will show what FL pattern under a sph CL
H touch V pooling
examples of recognition acuity for toddlers/preschoolers
HOTV matching Tumbling E, landolt C Lea symbols Allen pictures american optical pictures
for what infection might we do a Wright-Giemsa stain? looking for?
HSV giant multinucleated cells
T/F: as a lens becomes more minus, the front surface steepens
FALSE - flattens. BACK surface will steepen. (lab does it to minimize abbs.) conversely, higher plus lenses have steeper front & flatter back.
Dx numbers for DM: FBS = 2 hour plasma GL (oral/OGTT) = HbA1c =
FBS = 126 mg/dL OGTT = 200 HbA1c = 6.5 pt with hyperglycemia Sx/crisis may show random plasma glucose of 200 mg/dL
4 risk factors that increase risk for wet AMD
HTN Soft drusen Smoking Focal hyperpigmentation
Leber's hereditary optic atrophy
Leber's hereditary optic atrophy. The family ocular history reveals a male sibling with the same condition, which suggests a hereditary etiology. The fundus photos reveal optic nerve head pallor. Leber's is more common in males vs. females, and smoking is a risk factor. Vision loss can be sudden with variable field defects. Leber's hereditary optic neuropathy is caused by a mutation of maternal mitochondrial DNA. Genetic testing is recommended to confirm this diagnosis.
amiodarone ocular AE
NAION anterior subcap crystals whorl keratopathy
CRA forms 2 cap networks where? which is bigger?
NFL and INL INL is bigger bc it has to supply more things (horizontal, amacrine & BP cell bodies)
Kearns-Sayre syndrome
NMJ disorder due to mitochondrial abnormalities; can affect EOM movements Triad - progressive external ophthalmoplegia, salt/pepper fundus, 1+ systemic complication
what nerves go thru CTR
NOA nerves (nasociliary, oculomotor, abducens)
Myasthenia gravis is an autoimmune disease that affects which of the following types of receptors in the body? Nicotinic acetylcholine receptors Muscarinic acetylcholine receptors Alpha-adrenergic Beta-adrenergic receptors Adenosine receptors
Nicotinic acetylcholine receptors Myasthenia gravis is autoimmune neuromuscular disease in which circulating antibodies mediate damage and destruction of nicotinic acetylcholine receptors in striated muscle. The subsequent impairment of function at the neuromuscular junction results in weakness and fatigue of the skeletal musculature (with no affect on cardiac or involuntary muscles). This disease most commonly occurs in women and typically presents in the third decade of life. The earliest presenting signs of this condition are usually the development of ptosis or diplopia.
avg RE and axial length in full term newborns
RE +2.00 axial 16 mm (compared to adult avg 22) 50% have cyl (avg 2.00 D) but decreases to 0.50 or less within 2 years
who is refractive lens exchange done for? vs. implantable collamer lens (ICL)?
RLE = pts who are already abs presbyopes so they dont need to accom ICL = reversible, lens implanted either in front of or behind iris without removing crystalline lens
most common retinal dystrophy? macular?
RP stargardts
Between which areas of the retina does fluid accumulate in a patient diagnosed with central serous retinophaty
RPE and neurosensory retina
Which of the following acquired color vision deficiencies would you MOST expect to see in optic nerve disease and macular disease, respectively? Blue-yellow, rod monochromacy Red-green, blue-yellow Blue-yellow, red-green Red-green, rod monochromacy
Red-green, blue-yellow Dr. Kollner, an ophthalmologist, reviewed an extensive amount of literature on the nature of color vision impairment in patients with acquired ocular diseases. He concluded that most patients with diseases of the optic nerve tended to have difficultly discriminating red from green hues, while most patients with retinal disease (primarily macular) possessed a greater loss of discrimination between blue and yellow hues. This general dichotomy of red/green defects in optic nerve disease, and blue/yellow defects in macular disease has since come to be known as Kollner's rule. It is important to note that not all cases of acquired color vision deficiencies conform to this rule, however this theory holds true for the majority of patients.
A 12 year-old patient is seen at your office complaining of distance blur. Cover test reveals 4 prism diopters of exophoria at near. Subjective refraction reveals -2.25 DS OU. The patient returns 4 weeks later and reports that her vision is clear at distance with the glasses, but when she reads her eyes become fatigued and she reports frontal headaches, all of which she did not experience prior to getting her glasses. What is the MOST likely etiology of her headaches while reading? Resultant esophoria at near induced by her glasses The pantoscopic tilt is incorrect and is inducing unwanted astigmatism The optical center of her glasses was measured too low Her glasses are too tight and are putting pressure on her temples
Resultant esophoria at near induced by her glasses Patients with myopia who are newly corrected may display esophoria at near when wearing their spectacle correction. Reading through minus-powered lenses causes an increase in the accommodative response as well as the vergence system, resulting in less exophoria or more esophoria at near. If enough esophoria is induced, symptoms of asthenopia can occur. For patients with mild amounts of myopia, the removal of their glasses while performing near, visually oriented tasks will typically eliminate ocular discomfort. Other options include prescribing a bifocal or a progressive addition lens (PAL). Research has demonstrated that myopic patients who possess esophoria at near may benefit from a bifocal or PAL, which may serve to slow down the rate of progression of myopia.
Decrease in what mineral (other than Vit A) leads to night blindness?
Zn deficiency --> decreased activity of enzyme retinol dehydrogenase, which is needed for vitamin A to function properly
Correct order of stages of human development during the prenatal period?
Zygote-> Morula-> Blastocyst-> Embryo-> Fetus
pilo has the exact same mechanism to lower IOP as
accommodation! contracts longitudinal muscle which pulls on scleral spur which pulls on TM => decr resistance => lower IOP
most common culprit for analiculitis
actinomyces israeli
AMPEE stands for? AW which HLA?
acute multifocal placoid pigment epitheliopathy HLA-B7 and HLA-DR2 (maybe just dr2)
Cholestyramine, Gemfibrozil & Niacin are all used for
lowering cholesterol (+ statins too)
MOA of cholestyramine? Rxed for?
lowers cholesterol bile acid-binding resin that prevents reabsorption of bile acids in intestine
how many mm is the macula? fovea? fovola? cells in each?
macula = 5.5 mm fovea = 1.5 mm (1 DD) foveola = 0.35 mm macula = 2+ layers of GCs Foveola = ONLY CONES, no GCs/BPs macula = 4mm temporal + 0.8 mm inferior to disc.
major diff btwn pellucid & KCN?
cornea in PMD protrudes SUPERIOR to the area of thinning GP lenses will position extremelyinferiorly often will cross the inferior limbus onto the sclera
Epithelial ingrowth
epithelial ingrowth tends to develop several days to weeks post-LASIK and initially presents along the flap edge interface. Ingrowth generally progresses at a slower rate than DLK and most likely will not present diffusely throughout the flap-stromal incision sites at a rapid rate. This condition is caused by the proliferation of surface epithelial cells into the corneal flap interface. A commonly accepted theory states that ingrowth may occur due to the interruption of contact inhibition. Epithelial cells will not migrate as long as they are surrounded on all sides by other epithelial cells. Once this contact is disrupted either by laser or a blade, cell migration becomes stimulated and the cells move to fill in the perceived corneal defect. Ingrowth is more commonly encountered after enhancement surgeries. Risk factors for ingrowth are increased for patients who are slightly older, those with epithelial basement membrane dystrophy, those with a history of recurrent corneal erosions, those who frequently rub their eyes, diabetic patients, and those with blepharospasm. Surgical factors that mitigate ingrowth include hyperopic LASIK, over-manipulation of the flap, over-irrigation of the flap, flap edema, overuse of topical anesthetics, poor blades, button hole flaps, thin, torn or irregular flaps, unstable flaps, flap striae, a displaced flap, flap re-lift after the initial surgery, and LASIK performed over RK.
what 2 drugs inhibit dihydrofolate reductase that ARENT ABs
methotrexate fluorouracil
Development of the eye is coordinated by the neural ectoderm and mesoderm. The embryonic fetal fissure is the last structure to close to allow for the development of what?
optic nerve fissure allows passage of the mesenchyme so that hyaloid A plexus can form -eventually hyaloid regresses, but it persists as the CRA posteriorly. closure = inferior (inferior coloboma most common)
Mercaptopurine MOA? used to Tx?
purine antagonist ALL, Crohns + UC
which abb can be controlled by choosing correct BC for a given back vertex power? how do we choose it?
radial astigmatism (aka marginal/obliqu astig) controlled by choosing BC according to the flatter curve from Tscherning's ellipse
an endergonic rxn has higher conc of __ at equilibrium
reactants (endergonic requires energy, nonspontaneous, +deltaG)
snellen = _ acuity
recognition
Which of the following methods of drug administration is subject to first pass metabolism? Buccal Intrathecal injection Rectal Sublingual
rectal 1st pass = liver metab before going to systemic circ. buccal (against cheek) + sublingual avoid it intrathecal = injection into spinal canal (subarachnoid space)
ocular rosacea affects what type of glands
sebaceous (MGs!) rosacea = most common in northern european ancestry
what is the intrinsic vs extrinsic clotting mechanism
intrinsic = prothrombin=>thrombin production -thrombin acts on fibrinogen => fibrin forms => creates net that entangles RBCs+platelets =>CLOT. extrinsic = receipt of signals from enzymes+other susbtances that don't reside in blood to cause clotting. triggered by injured vessels or tissue
Minus power can be added to the contact lens by
holding the suction cup (which is attached to the concave side of the lens) such that the central convex surface of the lens (F1 surface) is in contact with the sponge tool. Using water and polish, the lens is then lightly pressed against the sponge tool while rotating counterclockwise (the sponge tool will be revolving clockwise). The lens should be removed frequently and repeatedly checked to ensure that warpage is not induced as well as to verify that too much minus is not added.
Haab's striae
horizontal breaks in descemets membrane seen in primary congenital glacuoma
which corneal stromal dystrophy has hyaline deposits? amyloid? mucopolysaccharide? AW hyperlipidemia?
hyaline = granular amyloid = lattice mucopolysacch = macular hyperlipid = Schnyder's
What happens if oxygen isn't available at the end of glycolysis? What if it is?
Isn't: Pyruvate --> lactic acid Is: Pyruvate --> Krebs cycle
Chloramphenicol
Last resort, can cross blood aqueous barrier. Can cause bone marrow depression and aplastic anemia, gray baby syndrome, optic neuritis. Can also cross BBB so good for meningitis
Blepharophimosis
Lateral and medial canthals are fused together --> narrowing of the palpebral fissure Typically occurs in conjunction with telecanthus and epicanthus inversus (prominent nasal semilunar fold).
Flow of CSF?
Lateral ventricle --> intraventricular foramen --> third ventricle --> cerebral aqueduct --> fourth ventricle --> subarachnoid space
What is the most common stromal dystrophy
Lattice dystrophy
Which of the following is the MOST common STROMAL dystrophy? Granular dystrophy Epithelial basement membrane dystrophy Macular dystrophy Lattice dystrophy
Lattice dystrophy
Although the dorsal lateral geniculate nucleus is comprised of six layers, it can be divided into two distinct regions based upon neuronal size. Which of the six layers make up the region known as the magnocellular layers? Layers 2, 3, and 5 Layers 1 and 2 Layers 3 and 4 Layers 4, 5, and 6 Layers 1, 4, and 6
Layers 1 and 2
Mitral valve
Left atrium and left ventricle
What's the likely problem in decentered SCLs? How to fix?
Lens is too flat, will often ride high Steepen the BC
At what time period of the day would the aqueous humor production be least? 8 AM to noon Afternoon Midnight to 6 AM
Midnight to 6 AM
Kearns Sayre
Mitochondrial. Triad is EOM palsy, salt and pepper fundus and one or more systemic complications
Your last patient of the day insists on being fit with a soft toric contact lens. Her subjective refraction is -3.00 -2.50 x 178. Which of the following lenses would be the BEST choice to use as a trial lens for her fitting evaluation? -2.75 -1.75 x 090 +2.00 -2.25 x 180 -3.00 -0.75 x 180 -1.00 -2.25 x 180 -2.75 -2.25 x 140
-3.00 -0.75 x 180 It is not always possible to have the correct diagnostic contact lens on hand. When this situation occurs, it is best to focus on power and axis because this will give you, as the practitioner, a good idea of how the lens will fit on the eye. If the lens is stable with good movement and coverage, an over-refraction will confirm the amount of astigmatism that is needed. If the lens is not stable and does not drape the cornea appropriately, then an over-refraction to confirm the astigmatism is unpredictable.
Average imbibition pressure (IP) of cornea
-40mmHg
what is the front surface power of an equiconcave lens with a power of -10.00
-5.00
corneoscleral drainage goes into episcleral veins. where does uveoscleral go?
-AQ seeps thru CB + surrounding tissues like sclera, eventually draining into choroidal vessels (& some studies say lymphatic system too) uvoescleral path doesn't have any identifiable channels or vessels
how do BBs work for GL
1) decr AQ production by blocking betas in the CB 2) increase outflow too
A prism deviates light by 5 degrees. What's the power of the prism (^)?
1* = 1.75^ 1.75(5) = 8.75^
1 degree = _ prism diopters
1* = 1.75^ prism diopters (1 degree = 1.75^)
Which of the following landmarks of an electrocardiogram represents repolarization of the atria? T wave Your Answer Atrial repolarization is obscured by the QRS complex P wave S wave PR interval Q wave
Atrial repolarization is obscured by the QRS complex
Which 3 of the following serve as muscular boundaries of the superior carotid triangle? (Select 3) A) Styloglossus B) Sternocleidomastoideus C) Sternothyreoideus D) Sternohyoideus E) Posterior belly of the digastricus F) Omohyoideus
B) Sternocleidomastoideus E) Posterior belly of the digastricus F) Omohyoideus
Familial hypercholesterolemia is the result of a defect to what structure? Very low-density lipoprotein receptor defect Low-density lipoprotein receptor defect High-density lipoprotein receptor defect Chylomicron receptor defect
Low-density lipoprotein receptor defect
Familial hypercholesterolemia is the result of a defect of
Low-density lipoprotein receptor defect which causes elevated *blood levels* of cholesterol
What is the common unit for luminous power? Lumens/square foot Foot-lamberts Candelas Lumens
Lumens
Activities that increases IOP
Lying down Blinking Coughing Blepharospasm Tobacco usage
Borrelia burgdorferi
Lyme disease
3 conditions AW presenile cats mnemonic
MAD myotonic dystrophy atopic dermatitis DM
how to calculate max ESR for males vs. females
MALES: age/2 FEMALES: age+10 /2
SLE
Butterfly rash (redness of cheek and nasal region.) For rosacea look for telangiectasia
Medicamentosa
Ocular reaction to medication or preservative. Get pain, FBS, SPK, redness, ulceration, scarring, photophobia
Type of congenital cataracts that is characteristic of galactosemia
Oil droplet opacities
5th order aberrations
Only happen with extremely dilated pupils
CN IV palsy
Only one that is contralateral, because it is the longest and thinnest nerve
CN III aberrant regeneration
Only with traumatic or compressive because nerves aren't permanently damaged in microvascular CN III palsy
which condition is characterized by the potential for glaucoma and has a central corneal opacity?
Peter's anomaly the only iridocorneal condition with CORNEAL issues
Thordiazine - what's it for, ocular adr
Phenothiazide for schizophrenia, psychosis Can result in retinopathy - salt/pepper changes in midperiph and posterior pole, decrease in BCVA, poor dark adaption
Stiles Crawford Effect I
Photoreceptors are more sensitive to light rays from the center of the pupil than to light rays entering from periphery
Characteristics of retinal photoreceptor cells
Photoreceptors hyperpolarize in response to a light stimulus Photoreceptors release less neurotransmitter in response to light Photoreceptors produce graded potentials
What does the pons do?
Regulate information between the cerebellum and the integration centers of the forebrain
If a patient accepts cylinder power 90 degrees away from the axis of delivery means
Rejection of astigmatism correction
Common systemic cause of Bell's
Sarcoid
What test is specific in differentiating between aqueous tear deficiency from MGD
Schirmer I test
How does hydration of sclera compare with cornea?
Sclera is more dehydrated (65% water) compared to cornea (78% water) because it has fewer GAGs (which are neg charged and attract water)
Peak scotopic and photopic sensitivity?
Scotopic - 507 Photopic - 555
Sickle cell ret
Sea fan neo is from AV anastamoses of existing capillary networks
Defocus and astigmatism are known as
Second-order aberrations
Primary v. secondary optic atrophy
Secondary - becomes swollen then atrophies Primary - just goes from healthy to atrophied
Vergence fixation disparity curves
Y intercept = Fixation disparity X intercept = The heterophoria Eso is up and exo is down BO is to the right and BI is to the left Steeper slope indicates poor adaptation
gonococcal infecion characteristics
YES PAN - Profuse conjunctival purulent discharge - Eyelid tenderness and edema - Severe conjunctival chemosis and hyperemia - Pseudomembrane formation can occur - Lymphadenopathy is typically prominent - N. gonorrhoeae can invade an intact epithelium; therefore peripheral corneal ulceration can occur if conjunctivitis is not treated properly - In severe cases, the ulceration can extend centrally, and eventual corneal perforation and endophthalmitis is possible - Gram staining will reveal a Gram-negative organism with a kidney-shaped diplococcic appearance
which corneal condition causes MORE pain than expected on exam
acanthamoeba early = mild SPK but horrible pain late - ring ulcer (bad - needs transplant)w
when do these mature: accom, divergence, convergence, disparity vergence, saccades, pursuits, stereo
accom: 3-4 mo divergence: 1 month convergence: 2 months disparity vergence: 6 months pursuits: 4 months saccades: start earlier than pursuits, but not super accurate until 6 mo (series of saccades vs. 1 good one) stereo appears @ 3-5 mo, adult level by 7 mo. 1 min arc stereoacuity by 24 mo (infants have very large depth of focus)
We taper oral steroids to avoid __
adrenal gland suppression (want adrenals to slowly ramp up endogenous steroid production)
which would prob cause the worst chemical burn? A. battery acid B. Airbag residue C. pava spray
airbag residue
endpoint of fan chart =
all clock lines look equally black & dark. when adding cyl power, if reversal occurs for lines that aren't perpendicular to your axis, then your initial axis is not correct.
why do guttata, blebs, or endothelial folds from
all in the event of hypoxia
DEEP lamellar kplasty replaces what
all opaque corneal tissue is removed almost all the way to Descemets -indicated in pts who have corneal disease involving 95% of corneal thickness, but healthy endo & unbroken descemets
Which one of the patient's medications is MOST likely to make his tinnitus worse?
aspirin
presence of a pigment demarcation line (aka high water marks) means RD is at least how old
at least 3 months old tends to LOSE pigment with age pigment usually convex compared to ora represents sites of increased adhesion
Elschnig pearls
commonly cause posterior opacification of the intraocular lens implant (IOL). This is due to the fact that residual lenticular equatorial epithelial cells left at the time of surgery may proliferate, migrate into the posterior visual axis and cause the appearance of bubble-like vacuoles on the posterior surface of the IOL, causing decreased visual acuity. This condition is best visualized via slit lamp and retroillumination on a dilated eye.
MOA of tamoxifen
competitive partial agonist inhibitor of estradiol @ the estrogen receptor.
Pneumothorax
collection of air in space around lungs
rod & cone recovery times (regen) in dark adaptation curve
cones = 10 min to fully recover rods = 35 min @ the rod cone break, rods become more sensitive than the cones
describe salt + peper fundus cause?
congenital syph salt = yellow-red areas of atrophy pepper = pigment clumps
Ruffini endings (aka Merkel discs) respond to
constant pressure + touch temps above 45*C (rapid changes in pressure/touch = paccinian)
3 common AE of morphine
constipation resp dep nausea, vomiting, dyspepsia, dry mouth
role of midbrain
coordinate visual, auditory, and tactile input.
excitation peak & emission peak of FL
excitation = 490 (blue) emission = 530 (green) fluorescence = excitation to a emit a longer wavelength (higher freq)
T/F: HSV can cause a granulomatous uveitis with iris atrophy, fine or stellate-like KPs and an increase in IOP
false - NON-granulomatous, but the rest is correct!
T/F: hydroxyamphetamine won't dilate a normal pupil.
false - dilates normal what dilates normals? cocaine + hydroxy. apra + 1% PE do not dilate normals.
t/f: crown glass has lots of abberations
false - it has the highest abbe value
T/F: nasolacrimal obstruction causes pouting puncta
false - its pretty far from puncta, no effect on it pouting = canaliculitis
T/F: controlled type 2 DM is a contraindication for lasik
false, as long as no retinopathy present
Pt is corrected by -5.00 CLs and has amp = 2.00 D. what's his range of clear vision uncorrected?
far point = 1/5 = 20 cm near point = 1/7 = 14 cm 14 - 20 cm. 5 D uncorrected myopia is like accommodating 5 D add the 2 D amp => +7 D near point.
AE of kenalog injection
pain on injection, temporary skin atrophy, subcutaneous white deposits, depigmentation of the eyelid at the injection site, retinal and choroidal vascular occlusion, and increased IOP
which EOM would not be affected by a tumor on the circle of zinn
inferior oblique (the only EOM whose origin is anterior to globe)
A healthy retinal nerve fiber layer is thickest at which portion of the optic nerve head?
inferiorly (2nd = superiorly) ISNT! temporal = thinnest - it's the PMB but they're so small & compact that it isn't thick
what is the only CN 3 subnucleus that is unpaired
levator subnucleus -caudal midline -1 subnuc innervates both levators (all the EOMs here have 2 subnuclei, one on either side)
who is CK done on
low hyperopes (0.75 to +3.00) with less than 0.75 D cyl.
why is sabourads agar good for fungi
low pH inhibits most bacteria
Meissner's corpuscles respond to
low-frequency vibrations in skin (superficial, adapt slowly)
weakness of only lower left side of face = what defect
right upper motor neuron (stroke) -damage to right corticobulbar tract
tinea =
ringworm fungal skin infection like athletes foot
4-2-1 rule
risk for becoming PDR Hemes in 4 quadrants Venous beading in 2 IRMA in 1
use what stain for conj squamous cell
rose bengal
most common 1* site that causes 2* choroidal melanoma
lung also breast in women occasional from GI or kidney
what do these test function of: photostress recovery brightness comparison red cap desat
macula = photostress ON = brightness comparison + red cap desaturation
during retinal develop, when does macula begin differentiation?
macular area begins differentiation first but is the last to develop completely.
what is a subtractive color mixture
mixtures transmit less light when combined than either of the two sources individually.
Pleurisy
painful ventillation due to inflammation of pleurae (ex. pneumonia)
most common early pattern of a GL VF defect
paracentral scotoma (70%) (typically small & relatively steep depressions; most commonly observed just supero-nasal to fovea) -
scabies =
parasitic mites that burrow under the skin and cause itching, rashes, and blisters. The condition is spread via close contact with infected people or infected linens or towels
For a given reaction, an overall change in free energy that is negative (-deltaG) is indicative of what? favors forming reactants or products?
rxn is exergonic. ie. spontaneous ie. produces energy (doesn't require it) ie. energy of reactants is greater than energy of products => product formation causes release of energy. favors products (higher conc of products than reactants at equilibrium)
blue-gray stromal opacities =>
salzmanns nodular degen
methylene stains
same as rose/lissamine plus corneal NERVES
candle wax drippings =
sarcoid vasculitis
cotton-ball opacities =
sarcoid vitritis
myelin in PNS = what cells? how do they differ from CNS myelin cells?
schwann cells -encased in BM called neurillema -> allows regeneration (CNS neurons can't regenerate)
what is spherical aberration
occurs when parallel light rays incident on the cornea and lens that are located further away from the visual axis are bent to a greater degree than axial rays, resulting in an image that comes to a point focus in front of the retinal plane.
what congenital cats are AW galactosemia
oil droplet opacities galactosemia = cant metab galactose properly
myelin iN CNS = what cells how do they differ from PNS myelin cells?
oligodendrocytes PNS schwann cells are encased in BM called neurillema -> allows regeneration (CNS neurons can't regenerate)
dichromacy
one of the photopigments is missing; the type of dichromacy is categorized based on which photopigment is lacking. A deuteranope is missing chlorolabe; a tritanope is missing cyanolabe, and a protanope is missing erythrolabe.
which purkinje image(s) are real & inverted
only image 4
anterior ciliary A's and LPCAs are both branches of
ophthalmic
Medial+lateral palpebrals are branches of
ophthalmic artery
what drug inhibits neuroaminidase
oseltaivir prevents spread of flu virus across resp mucosa
bone is derived from
osteoblasts (chondroblasts = cartilage)
Conn's syndrome
secondary to an aldosterone-producing adenoma of the adrenal glands
Pancreas (alpha cells)
secrete Glucagon
during development the outer optic cup becomes __ and inner becomes __
outer = RPE inner = retina
PP releases
oxytocin + ADH
kid has itchy lids with PAN. no allergy or bleph signs. DDx?
pediculosis! -nits -blood-tinged debris -PAN
periorbital AE of prostaglandins? signs?
periorbital fat atrophy signs of PGA periorbitopathy = -increased inferior scleral show -UL ptosis -dermatochalasis involution -slight ENophthalmos -atrophy of periorbital cells -deepening of UL sulcus
What part of retina is most sensitive to flicker? why?
peripheral retina (magno - "where"/motion, good temporal resolution + more summation) explains why chance of perceiving flicker is greater for a larger stimulus.
name the subdivisions of the frontal nerve (NFL/v1)
supraorbital supratrochlear
branches of frontal nerve (the F in NFL/V1)
supraorbital & supratrochlear
3 most common diseases that can cause a granulomatous uveitis
syphilis sarcoid TB (note- herpes is infectious but NON-granulmatous)
an endergonic rxn has what deltaG? favors forming reactants or products?
positive deltaG (free energy) ie. requires energy ie. non-spontaneous favors reactants (higher conc of reactants than products at equilibrium)
stands for: RK PRK
radial keratotomy PRK = keraTECTomy
what abb is AW a "teacup and saucer" image
radial/marginal astig. teacup = tangenital rays saucer = saggital rays RA = from asymmetry btwn the tangential & saggital meridians
Pacinian corpuscles respond to
rapid pressure changes related to vibrations & touch located in deep dermis, some internal organs & in membranes that lie close to freely-moveable joints (constant pressure/touch = Ruffini endings)
as radius becomes steeper, what happens to CT
thicker
thinnest + thickest parts of iris
thinnest = root (vulnerable to trauma) thickest = collarette
t/f: sclera is avascular
true
T/F: plateau iris pts typically have a normal AC depth
true iris plane is just flat rather than bowed
t/f: vogts striae often disappear when external pressure is applied to globe
true vogts = vertical = deep stroma
Soft contact lenses are typically fabricated flatter than the actual corneal curvature. What is used to compensate this factor
Adding 0.8 mm to the flattest keratometry reading
what is Gemfibrozil? used for?
LOWERS CHOLESTEROL fibric acid derivative decreases VLDL + LDL bc acting as a ligand for nuclear transcription receptor PPAR-a
PRs and RPE get blood from (3)
LPCAs SPCAs anterior ciliaries (all from choroid)
Most common type of (secreting) pituitary tumor?
Lactotrophic adenoma
what med is most likely to cause a yellow/green tinge to vision
Lanoxin (Digoxin) (xanthopsia) -also can cause blur + halos around lights
Using the Von Graefe method to determine the amount of phoria present at near on your patient, she reports that the targets are lined up vertically with 8 base in prism before the right eye. What conclusion can you deduce from the above results?
pt has 8^XP
which is NOT used as a chemo agent? -tamoxifen -methotrexate -azithioprine -cyclosporine
tamoxifen
the entrance & exit pupils of a reduced eye are
the images of the aperture stop (if they exist) if there are no lenses behind aperture stop, then AS = exit pupil entrance pupil = image of AS thru any lenses in front of it
describe fuchs onset? gender? early vs late Sx
-early signs @ 30-40, Sx at 40-50, >women -often inherited (AD) -early Sx = glare, light sensitivity later Sx = pain (bullae) + decr VA (edema)
which veins drain schlemms (4)
-external collector channels -deep scleral venous plexus -intrascleral veins -episcleral veins NOT VORTEX (thats choroid)
the vitreo-retinal attachments from strongest to weakest are
1. ora 2. posterior lens (hyaloideocapsular ligament of Weiger) 3. optic nerve 4. macula 5. retinal vessels
acronyms for the bones of the orbit
2-2-3-4 roof: Front-Less lateral: Great Z floor: My Pal Z's medial: SMEL
which cell types are found in foveola? which retinal layers?
3 cell types: PRs, glial, Muller 6 layers: RPE, PR, ELM, ONL, Henle, ILM (no BP or GCs so no INL or NFL)
Which of the following is correct: 1. Upon ADDuction 23*, SR is 1* elevator 2. Upon aBduction 51*, IO is 1* elevator 3. Upon aBduction 23*, IR is 1* depressor
3. Upon aBduction 23*, IR is 1* depressor
macula diameter
5.5 mm
which CN has 3 types of fibers (sensory, voluntary motor, involuntary motor)
7
how many bones make up the orbit
7 frontal, sphenoid, ethmoid, lacrimal maxilla, palatine, zygomatic
posterior pigmented iris epi is continuous with: A. NPCE & neural retina B. Pigmented CB epi & RPE C. Neither
A. back of iris is pigmented, but it eventually becomes 2 structures that are NOT pigmented. (NPCE + retina)
fuchs is what inheritance
AD
inheritance of EBMD
AD
thickest region of rods in retina is: A. Parafovea B. 6 mm from center of foveola C. just outside the perifovea
C - just outside perifovea (4.5 mm /18* outside fovea) there are no rods until just outside the perifovea.
which is the most anterior structure in the angle? A. Schlemms B. TM C. Schwalbes line
C. Schwalbes line the most posterior structure = peripheral iris
which CN is the "student nerve"
CN 11 head turning & shoulder shrugging
which CN does head turning & shoulder shrugging
CN 11 (accessory) the "student nerve"
which 2 CNs carry parasymps & which receptors do they use @ targets
CN 3: -ciliary body = M2, M3 -sphincter = M3 CN 7: lacrimal gland
A lesion of which CN would cause inability to close lids tightly
CN 7
A lesion of which CN would cause loss of reflex tearing
CN 7
taste anterior 2/3 tongue =
CN 7
angle structures from posterior to anterior (in gonio view, this is bottom to top)
I Cant See This Shit Iris CB Scleral spur TM Schwalbes line
upon aBduction 23*, which muscle is 1* depressor
IR
Schisis is most common where in the retina
IT and ST
2 types of schisis =
Juvenile: X-linked (boys) Senile: occurs with aging, not hereditary
what nerve innervates lateral conj & lateral upper lid? what nerve does lateral lower lid?
LACRIMAL nerve (NFL/V1)= Lateral upper lid/conj ZYGOMATIC nerve = lateral LL
deviation of uvula to the RIGHT indicates a lesion where
LEFT vagus nerve
which areas of the eye have nonfenestrated caps? fenestrated
NON: iris/retina FENESTRATED: CB + choroid
retinal layers in order:
RPE, PRs, ELM, ONL, OPL INL, IPL, GC, NFL, ILM
most likely area for a retinal tear
RT (atrophic holes,
lesion @ ciliary ganglion can cause
adies tonic pupil dx with 0.125% pilo
Which of the following options should not be included in the management of acanthamoeba keratitis? cycloplegic agent tid polyhexamethyl biguanide (PHMB) drops every 1hr amphotericin B propamidine isethionate (Brolene) drops every 1 hr
amphotericin B
what sensory function does CN 7 have
anterior 2/3 taste
1* contributor to iris color =
anterior border layer
where do CN 3 parasymp fibers begin? path?
begin @ edinger-westphal in midbrain => ciliary ganglion => CB (m2, m3) and sphincter (m3)
where do CN 7 parasymp fibers begin? path?
begin @ lacrimal nucleus in pons => sphenopalatine(pterygopalpatine) gang. =>lacrimal gland (M2, M3)
rhegematogenous means
caused by retinal break (atrophic hole or tractional tear) but atrophic holes rarely lead to RD traction tear RDs = much more common
approx thickness of cornea, choroid, sclera + retina
cornea: 0.52 - 0.55 mm (centrally) choroid: 0.2 mm at PP, 0.1 at ora sclera: thickest 1 mm, thinnest 0.3 retina: 0.23 in PPM, 0.1 at foveola
what is the pupil response in adies
delayed light AND near response
function of vortex veins? how many per eye?
drain choroid, CB + iris 4-7 per eye.
list corneal layers & their approx thicknesses
epi - 52 um bowmans - 8-14 stroma - 450 descemets - 5-15 endo - 5
4 roles of CN 7
facial expression closing eyes lacrimation dampening sound
T/F: a pigment demarcation line is expected in retinoschisis
false - pigment line indicates a concomitant RD.
most likely causes of secondary (metastasis) eye cancer in men vs women
female - breast men - lung
lacrimal gland is in a fossa of what bone? gland is divided into 2 parts by what structure?
frontal bone tendon of the levator splits lacrimal into orbital+palpebral portions
where does vitreous have highest amt of collagen? least?
in areas of the tighest attachments (so ora has the most collagen) least collagen = central vitreous 1. ora 2. posterior lens (hyaloideocapsular ligament of Weiger) 3. optic nerve 4. macula 5. retinal vessels OLOMV
a cuneus gyrus lesion would give which defect within the macula - superior or inferior?
inferior VF defect cuneus = superior
Pt has pupil involving CN 3 palsy - be highly suspicious of an aneurysm where
junction of ICA + posterior communicating
there are no rods in fovea until...
just outside the perifovea where the rod ring is (thickest region of rods in retina) rod ring = 5mm outside fovea
what 2 involuntary motor functions does CN 7 have
lacrimation + dampening of sound
left optic tract carries?
left temporal + right nasal fibers
definition of premature baby (and thus at risk for ROP)
less than 36 weeks
optic foramen passes thru which bone
lesser wing of sphenoid
choroidal melanomas most often metastasize to where
liver
describe pathophys of Fuchs
loss of endothelial cells => stromal edema (BAD) => epi edema (WORSE) => bullae. painful.
all corneal dystrophies are AD except
macular (AR)
accessory lacrimal glands are responsible for __ tearing
maintenance
where does IO muscle start its course
maxillary bone
difference btwn maxillary bone & maxilla bone? which is in orbit?
maxillary bone = above maxillary sinus maxilla = upper jaw & pallate
where is edinger-westphal
midbrain (with cn3 nucleus)
An RD caused by neo is what type
non-rheg (vitreous just pulls retina off, there's no tear)
volume of orbit? what % is globe?
orbit = 30 cubic cm globe = 6.5 cubic cm (22%)
corneal stem cells originate from _ and become _ cells
palisades basal cells basal cells are the only layer that mitoses. stem cells mitose => make wing cells
thickest area of entire retina =
parafovea (ring around fovea)
what is the corona ciliaris
pars plicata (old latin term)
the most posterior structure in the angle =
peripheral iris
order of meninges surrounding ON? btwn which layers is CSF?
pia, arachnoid, dura (PAD) CSF is between pia & arachnoid
anterior iris epi is continuous with _ and _
pigmented CB epi & RPE
zonules begin from pars plana or plicata
plana
classic signs + sx of orbital cellulitis
proptosis + ophthalmoplegia fever + malaise
lacrimal gland is involved in _ and _ tearing, but not _ tearing
reflex & emotional NOT maintenance (accessory glands)
2-2-3-4 all have sphenoid except the floor is which order?
roof, lateral, floor, medial (counterclockwise from roof) Front-Less, Great Z, My Pal Z's, SMEL
Mullers is what type of muscle? innervation?
smooth muscle symps
what types of cells are phagocytes in retina
some neuroglia
superior retinal fibers --> __ gyrus inferior retinal fibers ---> __ gyrus
superior = cuneus inferior = lingual
cuneus gyrus = __ fibers
superior retinal fibers, including superior macula
zonules are created from what type of vitreous? course?
tertiary (within pars plana) zonules course from plana to plicata to lens.
henles fiber layer =
the OPL in the foveola it's like the equivalent of the NFL, but its axons of PRs instead. all the foveola really has is PRs with extended axons.
thickest/thinnest parts of choroid (mm)
thickest = PP (0.2 mm) thinnest = ora (0.1 mm)
thickest/thinnest parts of retina (mm)
thickest = PPM (0.23 mm) thinnest = foveola (0.1 mm)
where is cornea thickest, thinnest, steepest
thickest = peripherally (1 mm) thinnest = central (0.55 mm) steepest = central
Cells of the adrenal cortex and what they produce
"Run Forrest Gump" Glomerulosa --> salt (aldosterone) Fasiculata --> sugar (glucocorticoids) Reticularis --> sex (androgens)
#1 cause of ophthalmia neonatorum? onset?
#1 = chlamydial, 5-14 days post-partum gonorrheal develops within 2-5 days post partum gonorrheal is more seveere - hyperacute chlamydial = uni or bilateral, mild to moderate cjvitis aureus, haemoplilus, pneumoniae, ecoli, pseudomonas can also cause it
A real image is located 25.00 cm from a +15.00 D polycarbonate (n=1.586) lens in air. Which of the following equations can be used to determine the location of the object? (1/0.25)= (1.586/l) +15.00 (1.586/0.25)= (1/l) +15.00 (1/0.25)= (1/l) +15.00D (1.586/0.25)= (1.586/l) +15.00
(1/0.25)= (1/l) +15.00D Image & object are both in air
How to calculate minimum blank size
(Frame PD - Patient distnace PD) + A measurement. OR (Frame PD - Patient distnace PD) + ED. (whichever is larger)
etiologies of Salzmann's nodular degen? key finding?
(all have to do with chronic keratitis) -dry eye -trachoma -phlyctenulosis -interstitial keratitis BLUE-GRAY STROMAL OPACITIES
What class of anti-HTN drugs causes transient myopia?
(thiazide) Diuretics
Lens clocks can do what?
*Calculate* the base curve of an ophthalmic spectacle lens (but not measure it) Determine the add power of a multifocal lens Test for potential lens warpage Determine the amount of slab-off prism on an ophthalmic lens Calculate the thickness of a GP lens Determine the nominal (or approximate) power of an ophthalmic lens
A +3.00 D hyperope is corrected with a +1.50 D contact lens bilaterally. If he views a near object located at 22.0 cm, what degree of accommodation is required to achieve a clear retinal image (rounded to the nearest 0.25 D)? +7.50 D +4.50 D +6.00 D +1.50 D
+6.00 D The target requires +4.50 D of accommodation to be viewed clearly, which is determined by the taking the reciprocal of the target distance (in meters) (1/0.22= 4.55 D or +4.50 D). However, in addition to the target demand, he must also accommodate 1.50 D more as he is undercorrected by this amount at distance in order to ensure a clear retinal image.
A lens system in air consists of a +4.00 diopter and +6.00 diopter lens separated by 10 cm. What is the equivalent power of this optical system?
+7.6 D -- Fe = F1 + F2 - (t/n) x F1F2
Specific types of chocolate agar?
+ bacitracin --> specific for Haemophilus Thayer-Martin agar (has antibiotics) --> selective for Neisseria
what lens rack lens will neutralize -0.50 x 90 orientation of streak?
+0.50 streak oriented vertically
avg corneal eccentricity
+0.50 - 0.60 in humans higher = flattens more rapidly in periph. eccentricity = a measure of asphericity -indicates how cornea changes from curved center to flatter periph (PROLATE shape) aka the amt that it deviates from a perfect sphere (which has e = 0) e = 1 is a parabola normal cornea = prolate ellipse myope lasik cornea = oblate ellipsoid (e = -0.1 - 0.9 depending on how fast it steepens)
When a stenopaic slit is aligned horizontally, subjective refraction determines the best sphere to be -1.50 D. The slit is then rotated and the best sphere is measured to be +0.5 D. What prescription should be prescribed?
+0.50 -2.00 x90
How to extend range of keratometer
+1.25 --> add 8-9 +2.25 --> add 16 -1.00 --> subtract 6
A convex crown glass lens in air has a radius of curvature of 4 cm. What is the dioptric power of the lens?
+13.0 D -- The equation for the power of a curved surface is: D= (n'-n/r)
A convex crown glass lens in air has a radius of curvature of 4 cm. What is the dioptric power of the lens? -4 diopters +8.25 diopters +13.0 diopters -13 diopters -8.25 diopters +4 diopters
+13.0 diopters The equation for the power of a curved surface is: D= (n'-n/r) D= power of the lens (may also be notated as F or P) n'= 2nd index (image), n= 1st index (object) r= radius of curvature (in meters) D= (1.52-1.0)/ 0.04 D= (+)13.0 diopters Remember that converging (or convex) surfaces will have positive power, and diverging (or concave) surfaces will have negative power. If this question was changed to a concave glass lens, the radius of curvature would be negative; therefore, the power of the lens would be (-) 13 diopters.
Stromal swelling pressure
+55 mmHg
What is the average stromal swelling pressure of the cornea
+55 mmHg
Which of the following values BEST describes the average stromal swelling pressure (SP) of the cornea? +55 mmHg -55 mmHg +40 mmHg -40 mmHg +25 mmHg -25 mmHg
+55 mmHg
Average stromal swelling pressure (SP) of the cornea
+55mmHg
A lens system in air consists of a +4.00 diopter and +6.00 diopter lens separated by 10 cm. What is the equivalent power of this optical system? +7.6 diopters +12.4 diopters +10.24 diopters +10.0 diopters +9.76 diopters
+7.6 diopters De = D1 + D2 - (t/n) x D1D2 De = equivalent power, D1 = front surface power, D2 = back surface power t = thickness of lens system, n = index between the 2 surfaces In the above question, t = 10 cm (0.1 m), n=1.0, D1 = +4.00 and D2 = +6.00 De = 4 + 6 - ((0.1/1.0) x (4) x (6)) De = 10 - (0.1 x 4 x 6) De = 10 - (2.4) De = +7.6 diopters
worth four dot
- 2 horizontal circles = GREEN - top circle = WHITE - bottom circle = RED
CONFUSION VS. DIPLOPIA
- CONFUSION: simultaneous perception of 2 dissimilar images superimposed , to avoid fovea of deviating eye is suppressed - DIPLOPIA: simultaneous perception of 2 images of same obj in 2 diff positions, to avoid image from peripheral retina of deviating eye suppressed.
Most common cause of CRAO
Atherosclerosis related thrombus formation. Calcific is most dangerous
ANSI standards for cylinder axis
- For small cylinder powers of 0.25 D, the axis may deviate up to 14 degrees in either direction and still fall within tolerance - A cylinder power of 0.50 D may allow an axis variation of up to 7 degrees - 0.75 D of cylinder power may have a deviation of axis up to 5 degrees - For cylinder powers of 1.00, 1.25, and 1.50 D, the axis tolerance is 3 degrees in any direction - Cylinder powers of 1.75 or above are only allowed an axis deviation of 2 degrees
Intradermal Nevi
- MOST COMMON AQUIRED NEVI - completely confined to dermis - raised flesh colored (non pigmented)
Macule Plaque Papule Nodule Vesicle
- Macule: color change (hypo, hyper, erythematous) w/ smooth surface surface is smooth). < 1.5cm in diameter - Plaque: >0.5cm palpable but *flat* lesion of the skin, may have well-defined or ill-defined borders. - Papule: <0.5cm diam, solid *elevation* of the skin. - Nodule: a solid area of elevated skin; a papule that is enlarged in three dimensions (height, width, and length). - Vesicle: <0.5cm, small *fluid-filled* lesion
stereopsis tests
- Random dot E; Titmus; Randot--> REQUIRE POLARIZATION GLASSES - Lang stereo test --> NO glasses req., goof for uncooperative children; uses a random dot stereogram to test for bifixation
torsional misalignment of OBLIQUE muscles
- SO = intorts ("SIN") - IO = extorts if left SO cannot intort anymore (broken) going to tilt head to RIGHT to compensate
refractive correction in children
- cases of HYPERMETROPIA (children presenting up to 4D hyperopia) with good acuites/no complaint--> NO RX NEEDED - hyperopia GREATER THEN 4.00D/complaints of near vision--> RX 2/3 OF FULL CYCLO - if ESOT exists --> RX FULL CYCLO (helps reduce angle of dev. by dec. amt of accom needed at near.
VISUOSCOPY
- monocular tests for EF - center of target is where patient wants to look - count INNER (CENTER) circle as 1 ...then has mark as 2 ...etc..
Junctional Nevi
- nevus cells located in junct of epidermis/dermis; flat brown/black
Monocular deprivation
- once animal/human is beyond critical period, monoc deprivation has NO EFFECT on cortical cells - sutured/patched during critical period, many/all cells in cortex will become monoc and react to stimuli presented to the NON deprived eye - cat crit period = first 3 mo. of life - human = first 2 years of life , over by 7-9 years
concomitancy
- primary deviation = non paretic eye fixating - secondary deviation = paretic eye fixating - deviation appears GREATER when deviated eye fixating ; also GREATER towards side of affected muscle
Blue Nevi
- spindle shaped Nevus cells - deep within dermis layer - covering epidermis is normal leading to bluish colored lesion
Conditions that falsely lower HbA1c levels?
-Any process that *shortens* the lifespan of erythrocytes (e.g. hemolytic anemia, chronic kidney or liver disease) -Vitamins C and E (by inhibiting glycosylation of glucose to hemoglobin) -Pregnancy -Splenomegaly -Rheumatoid arthritis -Certain medications (antiretrovirals, ribavirin, and dapsone) -Hypertriglyceridemia
Fish oil relationship to cholesterol levels?
Can INCREASE LDL levels - but the benefits of fish oil outweigh the rise
Cornea vs. sclera: Thickness Strength Collagen organization
Cornea is thicker, stronger, and more organized
hen determining a newborn's APGAR score, what 5 items does the physician evaluate?
-Heart rate -Respiratory effort -Muscle tone -Reflex irritability -Color
How does power of cornea/lens change as eye grows?
Cornea loses 4-5D of power Lens loses 20D of power
Conditions that falsely elevate HbA1C?
-Iron deficiency anemia -Any process that slows erythropoiesis increases A1c by maintaining an *older* erythrocyte cohort in the blood plasma (e.g. aplastic anemia) -Alcoholism -Hyperbilirubinemia -Certain medications (high doses of salicylates, chronic opioid use)
hollenhorsts come from? size? often cause?
carotids small plaques can cause CRAO but more frequently BRAO.
what does CN 9 innervate
-PAROTID -swallowing -gag -posterior 1/3 taste
Dermatological terms
-Plaque: a palpable but flat lesion of the skin that is greater than 0.5cm in diameter. Plaques may have well-defined, or ill-defined borders. - Macule: a localized area of color change without any associated infiltration or elevation (the surface is smooth). The lesion may be pigmented (as in a freckle), hypopigmentation (vitiligo), or erythematous (in a capillary hemangioma). The area of change is typically less than 1.5cm in diameter. - Papule: small palpable lesions in which there is a solid elevation of the skin. These lesions are usually less than 0.5cm in diameter, may be flat-topped or dome-shaped, and may be a single lesion or present as multiple lesions. - Vesicle: a small fluid-filled lesion that is typically less than 0.5cm in diameter. There may be a single lesion or multiple lesions. - Nodule: a solid area of elevated skin; a papule that is enlarged in three dimensions (height, width, and length).
The positive spherical aberration of the eye is typically offset by which natural property of the eye
Corneal asphericity
Ocular findings of OI
-blue sclera -keratoconus -megalocornea
4 drugs AW optic neuritis
-chloramphenicol -isoniazid -estrogen (HRT) -ethambutol NOT AMIODARONE amiodarone = NAION isoniazid+ethambutol = specifically retrobulbar optic neuritis
3 chlorpromazine ocular AE
-corneal endo pigment -anterior cortical stellate cats -color vision defects
list all the microvascular changes from prolonged hyperglycemia
-degen+loss of pericytes -thickening of cap BM + prolif of endo cells (=> occlusion, nonperfusion) -incr plasma viscosity, amplified platelet agg + adhesiveness (decr cap blood flow)
role of glutaraldehyde
-disinfectant + sterilizing agent that alkylates chemical groups in proteins + nucleic acids
early stargardts signs
-disproportionate vision loss (doesn't correlate w/ mild macular pathology) -yellow pisciform flecks scattered throughout PP
roles of neuroglia in retina
-glycogen metab (nutrients for retina) -immune (some are phago) -structure, support, protection
what makes the embryonic nucleus different
-highest conc of crystallins & thus the highest n, 1.50
name 4 conditions that can result in severe vision loss as a result of breaks in Bruchs within macula
-histo -exudative ARMD -lacquer cracks -angioid streaks
name the 4 parts of ON, their domains and approximate lengths
-intraocular (1 mm) - to lamina -intraorbital (30 mm) - lamina to canal -intracanalicular (6-10) - canal -intracranial (10-16) - canal to chiasm
astrocyte functions
-large role in BBB -remove NTs from synaptic zones -remove EXC K+
both ulcers & SEIs may present with round, grey-white/off-white lesions. what findings would point to an ulcer?
-lid edema -AC rxn, photophobia -lots of pain, rapid onset -discharge -thinning/epi defect that is same size or larger than infiltrate -circumlimbal conj injection (vs localized) -central (vs. peripheral)
describe corneal involvement in EKC
-most get diffuse fine SPK within first week 6-13 days: focal punctate epi lesions, appear elevated, stain day 14: SEIs under the focal lesions (20% of pts) SEIs may affect vision can perisist months to years, but typically resolve without scarring or neo.
3 signs of pediculosis
-nits -blood-tinged debris -PAN
5 drugs AW papilledema (incr ICP)
-oral prednisone -accutane -vitamin A -tetracyclines -birth control (NOT chloramphenicol)
describe the parts of a phosholipid
-phosphate group -choline group (polar) -2 FA chains (nonpolar) -all attached to glycerol (backbone)
how are selective cox-2 different in their effects?
-prevent prostaglandin formation @ sites of tissue inflam, but minimal effect on prosta production in gastric mucosa (lower risk of ulcer) -still have analgesic, antipyretic + anti-inflam effects, but do NOT impact platelet agg higher incidence of cardiac thrombotic events.
cornea = type _ collagen
1
incidence of steroid uveitis is higher in
10x higher in AA pts steroids should improve inflam, but paradox - it can cause the same condition it was meant to Tx.
SUN classification of uveitis
0 / <1 0.5+ / 1-5 1+ / 6-15 2+ / 16-25 3+ / 26-50 4+ / >50
Minimum center thickness for a GP
0.12mm
hirschberg/angle kappa
0.5 mm = 11 PRISM DIOPTERS
equivalent decimal acuity of 20/40
0.50 just divide 20/40...? NOT MAR
The amount of tonic accommodation in a normal individual is typically between
0.50 D and 1.50 D
1 prism diopter = __ degrees of deviation
0.57* (1 degree = 1.75^)
how many GC axons in a typical optic nerve
1 - 1.2 million
Jones 1=? jones 2=? how many minutes do you wait during Jones 1 test to see if NaFl is draining properly
1 = NaFl wait 5 min if positive (patent), don't proceed to jones 2. 2 = saline
Schirmer 1 is done with or without anesthetic? normal=?
1 = no anesthetic basal AND reflex >10mm is normal (schirmer 2 = basal only = >5 mm normal) jones test = integrity of drainage
how many DD is the fovea?
1 DD (1.5 mm)
20/20 = __ MAR = __logMAR
1 MAR 0 logMAR
How many nephrons per kidney?
1 million
3 reasons why VA not reach 20/20 until 3-5 years old
1) MYELINATION is incomplete until 2 years old 2) visual cortex immature - it begins to reach adult levels by 6 mo, but development continues for years 3) baby cones shorter+wider (length+density of cones hits adult levels around 4 yo) -retina develops from center to periphery until 1 year old, but it takes more months for PRs to migrate to fovea & for henle's fibers to develop => infants dont have bright foveal reflex until 15 months note-pattern VEP has shown 20/20 in 6-8 month olds! but thats not the same.
how long for entire corneal epi to regenerate
5-7 days
Which of the following provide blood supply to the eyelids? (Pick 3) 1. External carotid through facial artery branches 2. SPCA's 3. Muscular arteries 4. Ethmoid arteries 5. Branches of the ophthalmic artery 6. Medial and lateral palpebral arteries
1, 5, 6 facial artery (ECA) + Medial+lateral palpebrals are branches of OA!
blood pressure cuff size
1. Cuff too small: falsely elevated reading 2. Cuff too large: falsely low reading
what is used to Tx CHF
1. Glycosides (digoxin) 2. Diuretics 3. ACE inhibitors (-pril) 4. Losartan (angiotensin receptor blocker) BBs have been used but no evidence. Not Ca blockers; those are just for HTN. Not Amiodarone, that's just arrhythmia.
All else being equal, cells found in which layer of the cornea consume the GREATEST amount of oxygen? A) Endothelium B) Bowman's membrane C) Stoma D) Epithelium
A) Endothelium
Prolonged HYPERglycemia (diabetics)
1. Degen and loss of pericytes 2. thickening of capillary BM 3. Proliferation of endothelial cells 4. Increased plasma viscosity
If the contact lens that you have calculated to provide the best fit and vision is not available in your diagnostic fitting set, how do u choose next contant lens
1. Find flatter fitting contact lens 2. Contact Lens Rx that would allow low minus over-refraction
If a -1.00 trial lens is added to a keratometer to extend the range in order to get a reading, how many diopters is needed to be subtracted to the drum reading to get an accurate value
6 D
the Munsell color appearance system says we can specify any color with what 3 numbers
1. Hue (wavelength/color) 2. Chroma (related to saturation) 3. Value (reflectance of sample - related to brightness)
Name 2 functions of the medial and lateral palpebral arteries.ion
1. Provides blood supply to the internal portion of the EYELIDS. 2. Provides oxygen to the anterior cornea (epithelium to anterior stroma) when the eyes are CLOSED. posterior cornea gets O2 from aqueous when eye closed. EYE OPEN = ENTIRE CORNEA gets O2 from TEARS/ATM
How to minimize spherical aberrations?
1. Radius of curvature that increases towards the periphery of the lens (the periphery of the lens is flatter than the center) 2. Plano-convex lenses; hyperopes - convex side as F1 3. Decreasing the size of the aperture/pupil.
by __ months old, all eye mvmts have usually reached adult levels
6 months
what enzymes are found in gluconeo that aren't found in glycolysis
1. fructose 1,6,biphosphatase (replaces/reverses phosphofructokinase) -fru-1,6-bisphos back to fru-6-phos. 2. glu-6-phosphatase (reverses hexokinase) G-6-P back to glucose. 3. phosphoenolpyruvate (PEP) carboxylase (reverses pyruvate kinase) -oxaloacetate back to phosphoenolpyruvate
4 -possible causes of an abnormally miotic pupil in which anisocoria is greater in dim light:
1. horners 2. argyll-robertson (normal near) 3. IRITIS 4. longstanding Adie's pupil (initially dilated but can become miotic over time. irregular +slow rxn to light)
2 types of limbal girdle
1. less common, clear zone btwn girdle & limbus, stays in peripheral cornea (early band ktopathy) 2. more common = contiguous with conj (no lucid interval), result of collagen breakdown in bowmans
2 major Zeis gland functions
1. lubricate lashes 2. assist Moll + MGs in producing lipid
A front surface, prism ballast, toric gas-permeable contact lens is indicated in two types of patients
1. patient that presents with a low amount of corneal toricity (typically less than or equal to 1.00 D) 2. when tested with a spherical rigid lens reveals an unacceptable amount of cylinder in the over-refraction (usually greater than or equal to 1.00 D). WHY? findings indicate the presence of residual or lenticular astigmatism that will need correcting in order to allow for the best visual acuity.
How does corneal involvement secondary to bleph stain?
1/3 inferior cornea
Fovea subtends a visual angle of how many degrees?
1.2 deg
Visual angle subtended by the fovea
1.2 degrees
Javals rule =
1.25*CA + 0.5 ATR
Average corneal refractive index?
1.3765 (rounded to 1.38)
how big is fovea (mm, DD)
1.5 mm (1 DD)
avg dimensions of ONH
1.5 mm H 1.75 mm V
What is the average diameter of the optic disc
1.5 mm in diameter horizontally and 1.75 mm in diameter vertically
Whast add would be Rxed for a pt whose near point is measured to be 33 cm when a +1.00 assisting lens is used? assume WD = 40 cm
1.50 D
Your hyperopic patient wishes to order progressive addition lenses (PALs). Her reading add is +2.50. How much yoked base down prism will be present in her progressive lenses? 5 prism diopters 0.83 prism diopters 1.66 prism diopters 1.25 prism diopters
1.66 prism diopters Generally multiply ADD x 2/3
A patient returns to your office reporting that her eyes feel strange when she reads 6 mm below the optical centers of her new glasses. The prescription in her right eye is -4.00 DS and -7.00 DS in her left eye. How much vertical prism is induced when she reads? 4.2 prism diopters base down 1.8 prism diopters base down 2.4 prism diopters base down 6.6 prism diopters base down
1.8 prism diopters base down Explanation Use the Prentice rule to solve this problem: prism diopters(pd) =d*F, where d= the distance from the optical center in centimeters and F= the power of the lens in the desired meridian in diopters. In this instance, the patient is looking through base down prism in both eyes, which will cancel some of the prismatic effect as the bases are aligned. Solving for the amount of prism on the right eye, pd=0.6(-4.00)= 2.4 base down prism. Solve for the left eye: pd=0.6(-7.00)=4.2 base down prism. Subtract the two to determine the total prismatic effect experienced by the patient: 4.2-2.4=1.8 base down prism. Alternatively, you can omit one of the steps by initially determining the total power difference in the vertical meridian between the two lenses, which is 3.00 D (7-4=3). Then you can multiply this power difference by the distance between the patient's line of sight and the optical center, which is 6 mm in this question. Pd=0.6(3)= 1.8 prism diopters base down over the left eye. Generally, vertical imbalances of smaller magnitudes do not pose too much of a problem for single vision lenses as the patient can tilt her head to re-align the optical centers with her line of sight, thus eliminating any possible diplopia.
Visual cycle
11-cis retinal to all trans retinal to all trans retinol to 11-cis retinol and back to 11-cis retinal. All trans retinal is reduced to all trans retinol and all trans retinol is transported to RPE
avg H & V diameter of cornea when viewed anteriorly? posteriorly?
11.7 10.6 circular from behind - both are 11.7! (due to anterior extension of opaque sclera superiorly+inferiorly)
find the prism induced in a +5 lens decentered by 2 mm down & 3 mm out
1^BD + 1.5^BO net prism = z2 = x2 + y2 sq root (1 + 1.5^2) = 1.8^ down + out.
onset of granular dystrophy?
1st decade
When is an EKC pt no longer contagious?
14 days post-innoculation, or when SEIs form
Schirmer 2 is done with or without anesthetic? normal=?
2 = YES anesthetic
Which of the following drops should be used with caution in a patient with pigment dispersion syndrome?
2.5% phenylephrine: Pupil mydriasis (particularly when caused by phenylephrine use) of a patient with PDS may cause an exacerbation of pigment release. It is therefore important to measure post-dilated IOPs.
PALs will induce how much yoked *base down* prism
2/3 * ADD power
5x mag microscope has what power lens (D)
20 D M = Flens/4 5 = F/4 F = 20 D
If a patients best corrected acuity is 20/100 in both eyes and the goal is to be able to watch television (say this requires approximately 20/50 acuity). What is the anticipated magnification this patient will need in a telescope to achieve his/her goal?
2x. 100/50 = 2x. divide denominator of actual acuity by denominator of goal acuity.
Surfaces of the gullstrand #2 eye
3 cornea ant and post lens
purley motor CNs =
3, 4, 6, 9
Which of the following values BEST describes the normal cellular density of the corneal endothelium? 1,000 cells/mm2 5,000 cells/mm2 3,000 cells/mm2 2,000 cells/mm2 4,000 cells/mm2
3,000 cells/mm2
Vernier acuity
3-5 seconds of arc
Typical vernier acutiy?
3-5sec arc
When does VA reach 20/20?
3-5yo
Tear thickness in a normal, healthy, young adult measures
3.0 micrometers
mean AC depth
3.4 mm
How long does it take rods to fully recover
35 minutes
peak of SF curve in adults? when does a child reach that?
4 cpd child reaches this by about 6 months old (from birth, CS function shifts up and to the right)
Approx vol of vitreou
4.0 mL
cornea = __ D in adults __ at birth
43 D 48 at birth (loses ~4 D by age 2)
What is the approximate average refractive power of the crystalline lens at birth
45 D
Lens at birth
45 D, will lose 20 D by the age of 6 in the process of emmetropization
power of cornea at birth =
48 D cornea loses 4 D by the age of 2 (emmetropization)
Telescope is marked 5x20 - what does it mean? What is mag? Diameter of exit pupil?
5x = mag 20 = size of objective Diameter of exit pupil = 2o/5 = 4 mm
Surfaces of the gullstrand #1 eye
6 ant/post cornea ant/post lens cortex ant/post lens nucleus
Height of a 20/20 Snellen letter?
8.73mm
Your trial frame refraction yields a distance prescription of -1.00 DS in both eyes of your 78-year old low vision patient. Using a +4.00 DS OU near prescription only with a CCTV set to 16x magnification, what is the equivalent power? 80 D 21 D 32 D 64 D
80 D Fe = (mag of relative distance)(Fadd) Fe = (16)(5) = 80 D
Modulation depth
= amplitude of luminance change (to perceive a stimulus as flickering) Shouldn't be too low --> will be perceived as steady
2 signs of bilateral trochlear palsy
>10* cyclodeviation on double MR RHT in left gaze LHT in right gaze (contralateral)
conj squamous cell most commonly where? in what pts?
@ limbus with a feeder vessel elderly white men use rose bengaal
Which is essential for epi cell tissue growth + maintenance? -vitamin D -vitamin A -vitamin B12 -vitamin C
A
Grades A-D fusion
A - instant fusion B - momentary dipl then fusion C - constant dipl D - suppression
A central retinal artery occlusion (CRAO) causes tremendous damage to the retina. How will the electroretinogram (ERG) of a person who has suffered a CRAO be affected?
A central retinal artery occlusion will cause a loss of the b-wave which is formed by responses from the bipolar and Muller cells, both of which are nourished by the central retinal artery. The a-wave results from excitation of the photoreceptors. The a-wave will not be lost in the event of a CRAO due to the fact that photoreceptors receive their oxygen supply via the choroid.
Tetralogy of Fallot
A congenital heart defect where there is a hole in between the ventricles of the heart and narrowing of the pulmonary valve, which causes right ventricular hypertrophy that subsequently overrides the aorta
Zero order
A constant characterized by axial asymmetry and a flat wavefront
A patient with high myopia undergoes ERG testing. Which of the following results is most likely to be observed
A decreased b-wave amplitude
A deficiency in which vitamin causes prolonged dark adaptaion?
A deficiency of vitamin A causes prolonged dark adaptation. Vitamin A is classified as a retinoid, and its active form is retinol. Retinol is necessary for the formation of rhodopsin, a pigment used by rods. Rods are most active in situations with dim illumination. Less rhodopsin results in fewer rods being able to respond in low levels of light, causing prolonged dark adaption.
The presence of foam at the canthus is thought to be pathognomonic for blepharitis. What is the direct etiology of the foam
A detergent effect from the altered meibomian gland lipids (saponification) *key diagnostic sign of MGD*
Brucke-Bartley effect
A flickering stimulus that is 10 Hz will appear brighter than a non-flickering light with the same average luminance. Also holds true for stimulus presentation duration - light that is presented for 50 milliseconds will appear brighter than stimuli presented for longer or shorter durations.
what is a keloid former
A keloid former is a patient who is prone to producing a lot of scar tissue in the event of trauma or tissue manipulation. scarring increases scatter, halos => decr acuity, or can cause under/overcorrection or undesired cyl
Causes of mechanical ectropion
A large lesion forms on the eyelid, which pulls the eyelid away from the eye
mechanical ptosis
A mechanical ptosis is one in which there is a gravitational effect of an eyelid mass or eyelid scarring. Retained contact lenses in the upper fornix, upper eyelid inflammation due to the presence of a chalazion, giant papillary conjunctivitis, post-traumatic edema, or a neoplasm/tumor could all potentially cause an observable ptosis.
Corneal microcysts
From 2 months of extended CL wear, are 15-20 mm in diameter and are irregularly shaped and show reversed illumination
Toxo gondii
A protozoa
Lens adjustment
A simple rule of thumb for frame adjustment is: -If the right lens is in -> move the right temple in (or left temple out) -If the left temple is in -> move the left temple in (or right temple out) -If the right lens is out -> move the right temple out (or left temple in) -If the left lens is out -> move the left temple out (or right temple in) If the frame is not straight on the face, it could be because of incomplete standard alignment, or because one ear of the patient is positioned slightly higher than the other. The solution is the same regardless of the cause of the misalignment: -If the right lens is up -> bend the right temple up (or left temple down) -If the left lens is up -> bend the left temple up (or right temple down) -If the right lens is down -> bend the right temple down (or left temple up) -If the left lens is down -> bend the left temple down (or right temple up)
Riddoch phenomenon
A stimulus is only observed when it is in motion, and cannot be detected by the observer when it is static. Seen in individuals who suffer from an occipital lobe lesion, optic nerve damage, or chiasmal damage
CRA and the ERG
A wave remains because photoreceptors are nourished by the choroid and thus unaffected. Loss of B wave because bipolar cells and muller cells are supplied by CRA
+1.50-1.50 x 090 is required to neutralize a reflex in retinoscopy with a working distance of 50 cm. What is the resulting NET retinoscopy finding?
A working distance of 50 cm creates a divergent wave of 2.00 D that is neutralized by retinoscopy in addition to the patient's refractive error. Therefore, + 2.00 D must be subtracted from the spherical portion of the findings. To determine how much to subtract from the gross findings, one must first calculate the reciprocal of the working distance in meters. In our case, 1/0.5 = 2. Therefore +1.50 (the spherical gross findings) -2 = -0.50-1.50 x 090. Remember NET is the final result, this is found after the working distance has been accounted for by subtracting the working distance from the spherical portion of the findings.
Sub-retinal hemorrhages occur at what level of the retina? A) Between the retinal pigment epithelium and the sensory retina B) Between the internal limiting membrane and the nerve fiber layer C) Between the inner and outer nuclear layers D) Between the retinal pigment epithelium and the choroid
A) Between the retinal pigment epithelium and the sensory retina
Which 2 of the following occur during accommodation? (Select 2) A) The equatorial circumference of the lens decreases B) The depth of the anterior chamber increases C) The posterior surface of the lens changes D) The intraocular pressure decreases momentarily E) The lens moves posteriorly
A) The equatorial circumference of the lens decreases D) The intraocular pressure decreases momentarily
What happens to the heart during contraction of the ventricles? A) The mitral and tricuspid valves close, the atria relax and the semilunar valves open B) The mitral and tricuspid valves open, the atria contract and the semilunar valves open C) The mitral and tricuspid valves close, the atria contract and the semilunar valves close D) The mitral and tricuspid valves open, the atria relax and the semilunar valves open
A) The mitral and tricuspid valves close, the atria relax and the semilunar valves open
which of these can cause a mucous tear deficiency (select all): A. ocular pemphigoid B. SJS C. ehlers-danlos D. vitamin A deficiency
A, B, D pemphigoid, SJS, vitamin A
Dacryoadenitis refers to an inflammation or infection of which of the following ocular structures? A. The lacrimal gland B. The puncta C. The lacrimal sac D. The nasolacrimal sac
A. Dacryoadenitis describes inflammation of the lacrimal gland, generally due to infection. The swelling is categorized as either chronic or acute. Acute presentations appear more commonly as a unilateral swelling of the upper eyelid, along with pain, excessive lacrimation, probable ipsilateral lymphadenopathy, and potential proptosis. If the condition is bilateral it is likely due to a systemic infection. Chronic dacryoadenitis is generally bilateral and presents with hard masses that are palpable at the location of the lacrimal gland. This form is often painless and caused by inflammatory diseases such as Grave's, Sjogren's, or sarcoidosis. The chronic type warrants further investigation in order to rule out a lacrimal gland tumor.
A young strabismic child presents at your office. Using visuoscopy you ask the patient to fixate the center of the target with their right eye (the left eye is occluded). The foveal reflex is positioned three hash marks to the LEFT of the center circle of the target. This finding suggests which type of fixation? (assume each hash mark is equal to 1 prism diopter) A. 4 prism diopters nasal eccentric fixation B. 4 prism diopters temporal eccentric fixation C. The patient does not possess any eccentric fixation D. 4 prism diopters inferior eccentric fixation E. 4 prism diopters superior eccentric fixation
A. Visuoscopy is an excellent technique to evaluate for eccentric fixation. This is performed by using the cross-hair target of your direct ophthalmoscope and projecting it onto the macula of the unoccluded eye. The patient is asked to fixate on the center of the target. No eccentric fixation is present if the foveal reflex aligns with the center of the cross-hairs. If the foveal reflex is to the left of the center (for the right eye), then the patient has nasal eccentric fixation. If the foveal reflex is located to the right of the target center, the patient possesses temporal eccentric fixation. The opposite holds true for the left eye (if the foveal reflex is to the right of the target center, the patient has nasal eccentric fixation). If the foveal reflex is located above the target, then the patient has inferior eccentric fixation, whereas a foveal reflex below the target is classified as superior eccentric fixation. In order to calculate the amount of eccentric fixation, you will have to know that from the center of the circle on the visuoscopy target to the edge of the circle is one prism diopter, and then each hash mark away from the center circle is an additional prism diopter. Therefore, the above patient has a total of 4 prism diopters of eccentric fixation (1 to the edge of the circle, and 3 for each additional hash mark).
What is the Interval of Sturm for a spherocylindrical lens with a power of +6.00 -2.00 x 090? A. 8.3 cm B. 25 cm C. 16.7 cm D. 20 cm E. 41.7 cm
A. 8.3 cm Explanation The powers in each meridian of the lens are +6.00 and +4.00. The Interval of Sturm is simply the distance between the focal point of each power. 1/+6.00 = 16.7cm 1/+4.00 = 25.0cm 25cm - 16.7cm = 8.3cm
Chronic blepharitis, if left untreated, can cause which of the following structural changes to the anterior ocular segment? A. Madarosis B. Distichiasis C. Hypertelorism D. Tristichiasis
A. Madarosis Explanation Blepharitis is a condition caused by pathogens, usually of Staphylococcus origin, that colonize along the eyelid margins. The bacteria produce exotoxins which take the form of flakes and are generally seen along the base of the eyelashes. Unfortunately, this condition is chronic but will wax and wane in its presentation. Long-term complications include madarosis (missing lashes), trichiasis, neovascularization of the eyelid margin, keratitis, erythema, phlyctenule formation and infiltrates. Patients may complain of dry, irritated eyes, stinging, pain, itching, frequent eye infections, foreign body sensation, and decreased acuity (if there is corneal involvement). Treatment includes eye lid scrubs, antibiotic ointments and sometimes transient topical steroid use to decrease lid inflammation (usually used in conjunction with a topical antibiotic). Occasionally oral antibiotics are prescribed, especially in the event of poor compliance. Distichiasis is a rare congenital phenomenon marked by an absence of meibomian glands. In the place of the meibomian glands is an extra row of eyelashes. Hypertelorism is a term used to describe the incidence in which the orbits are located quite far apart. This generally occurs along with other congenital cranium anomalies. Tristichiasis is a very rare occurrence in which a person possesses three rows of eyelashes.
Dacryoadenitis refers to an inflammation or infection of which of the following ocular structures? A. The lacrimal gland B. The puncta C. The lacrimal sac D. The nasolacrimal sac
A. The lacrimal gland Explanation Dacryoadenitis describes inflammation of the lacrimal gland, generally due to infection. The swelling is categorized as either chronic or acute. Acute presentations appear more commonly as a unilateral swelling of the upper eyelid, along with pain, excessive lacrimation, probable ipsilateral lymphadenopathy, and potential proptosis. If the condition is bilateral it is likely due to a systemic infection. Chronic dacryoadenitis is generally bilateral and presents with hard masses that are palpable at the location of the lacrimal gland. This form is often painless and caused by inflammatory diseases such as Grave's, Sjogren's, or sarcoidosis. The chronic type warrants further investigation in order to rule out a lacrimal gland tumor.
Patients with a history of Marfan's syndrome are MOST likely to experience crystalline lens subluxation in which of the following directions? A.Up and outward B.Down and inward C.Up and inward D.Down and outward
A. Upward and outward
which part of macula has thickest region of GC/BP cells? a. parafovea b. perifovea c. fovea
A. parafovea BP/GCs are pushed to periphery of foveola/fovea, which is the parafovea. thickest area of entire retina
Which of the folllowing is the most common primary pediatric orbital malignancy? A) Rhabdomyosarcoma B) Neuroblastoma C) Capillary Hemangioma D) Cavernous Hemangioma
A. rhabdo = rapid bone destructing tumor. Neuroblastoma = most common SECONDARY (metatstatic) in kids -arises from abdomen (poor systemic health) cap hemangioma = most common benign orbital tumor in kids; watch for deprivation ambly cav hemangioma = benign, most common orbital in ADULTS
Tear volume in a normal, healthy, young adult measures approximately between which of the following values? A.6.0-8.0 microliters B.2.0-5.0 microliters C.9.0-12.0 microliters D.17.0-20.0 microliters E.13.0-16.0 microliters
A.6.0-8.0 microliters Explanation Tear volume has been measured by several methods to be approximately 6-7 microliters in normal individuals, with lesser values occurring in conditions of aqueous tear deficiency. This has implications for drug delivery, since the normal ophthalmic drop volume varies between 25 and 50 microliters, effectively overwhelming the native tear value upon instillation.
When examining a patient, a pinpoint spot of the posterior surface of the lens known as Mittendorf's dot is seen. What is this a remnant of? A.Hyaloid artery B.Glial tissue of the optic nerve C.Vitreous D.Pupillary membrane
A.Hyaloid artery Explanation Mittendorf's dot is a remnant of the hyaloid artery and appears as a black dot on the posterior surface of the lens. Pupillary membrane remnants would be present in front of the lens and are a complex of fibers. Glial tissue of the optic nerve head is a remnant that is known as Bergmeister's papilla.
What is the name of the surgical procedure in which thermal laser burns are placed in the mid-periphery of the cornea in an attempt to steepen the corneal curvature? A.Conductive keratoplasty B.Radial keratotomy C.Limbal relaxation incisions D.Laser-assisted in-situ keratomileusis E.Photorefractive keratectomy
A.Conductive keratoplasty Explanation In cases where the corneal curvature must be steepened in order to correct for refractive error (hyperopia or presbyopia), conductive keratoplasty (CK) is a viable surgical option. Although this surgical procedure was used more often in earlier years, it is not currently as widely used as laser-assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). In comparison to CK, LASIK and PRK tend to be safe, have long-standing results, and more predictable outcomes. The CK technique involves using a radiofrequency probe to create burns in either one or two concentric rings in the mid-peripheral region of the cornea. These thermal laser burns cause subsequent stromal shrinkage, which results in an increase in the curvature of the cornea. This change in curvature typically decays over time, but the procedure can be repeated. Radial keratotomy is also an older surgical procedure in which a diamond blade is used to create several radial corneal incisions (the number and depth of the incisions depends on the refractive error) in order to flatten the corneal curvature in patients with myopic refractive errors. Limbal relaxation incisions are similar in that arcuate incisions are made on opposite sides of the corneal periphery in the meridian of the "plus" cylinder axis in order to create flattening of the steep corneal curvature (with some smaller steepening of the flat meridian) in an attempt to reduce the amount of corneal astigmatism. Photorefractive keratotomy (PRK) and laser-assisted in-situ keratomileusis (LASIK) are refractive surgery techniques that use an excimer laser to ablate corneal tissue to a certain depth in either the central cornea (to correct myopia) or peripherally (to correct hyperopia)
Kirby bauer agar diffusion is used for
AB susceptibility testing
-pril suffix =
ACE inhibitor
AREDS 1
ACE, zinc and copper. Got rid of vit A due to lung cancer. Increased vit E
Optic foramen
AKA optic canal. CN II and ophthalmic artery.
what are these units of: trolands lux lumens foot-lamberts
ALL RETINAL trolands = illumination lux = illuminance lumens = luminous power foot-lamberts = luminance
Visual acuities improving due to pinhole follows what principle of optics, assuming that no ocular pathology exist.
Depth of focus (range of distance in image space for which an object appears to be in focus)
What are catecholamines
Derived from tyrosine, then converted into NTs NE, epi or dopamine
Ankyloblepharon
Adhesion of a portion of the eyelids or complete fusion occurring secondary to injury, infection (trachoma) or tarsorrhaphy. This can also be congenital - ankyloblepharon filiform adnatum.
According to the American National Standards Institute (ANSI), what is the minimum center thickness allowable for high-impact prescription safety lenses made from polycarbonate?
ANSI requirements state that in order for a prescription lens to be deemed as high-impact, it cannot measure less than 2.0mm thick at its thinnest point and must pass the high-velocity impact test. Currently, only materials made from polycarbonate resins adhere to both of these requirements.
The above patient states that he requires side shields for his safety frame during performance of his work duties. Which of the following maintains compliance with ANSI?
ANSI states that the side shields must be placed onto a prescription safety frame, designated with Z87-2, in order for the whole frame to be considered a 'safety frame' and that the placement of compliant side shields placed onto a basic frame will not then result in that frame then being designated as a 'safety frame'. The side shields may be removable and need not be a permanent fixture in order for the frame to be deemed a 'safety frame'. The side shields must be able to withstand an impact of 150 feet per second at three specified points.
FL staining of CL shows vertical touch and horizontal pooling. What type of astigmatism does this eye have?
ATR
A pt is corrected by +2.00 +1.00 x180. does she have WTR or ATR
ATR (have to make it minus cyl first: +3.00 -1.00 x90)
type 2 hsensitivity rxns = mediator?
Ab-dependent cytotoxic rxns IgM + IgG + complement
Optociliary shunt
Abnormal venous communications between retinal and choroidal vasculature on the surface of the optic disc, indicative of chronic venous obstruction of a retinal vein
How do SCLs affect NCT measurement?
Above +3.00 --> overestimated IOP Under -6.00 --> underestimated IOP
Spherical aberration and accommodation
Accommodation reduces spherical aberration, and thus aging increases spherical aberration
Regarding the bioavailability of a steroid, which formulation allows for the BEST corneal penetration through an intact epithelium with topical application
Acetate > Alcohol > Phosphate derives
What 2 pupil anomalies will cause aniso worse in BRIGHT light
Acute Adie's tonic pupil Oculomotor palsy
Phacomorphic glaucoma
Acute secondary angle closure type of glaucoma - antero-posterior growth of the lens --> increase in iridolenticular contact --> pupillary block and iris bombe
Soft CL fitting
Add .8 - 1mm to the flat or average K, err on the side of going too flat
Formula to calculate necessary add
Add = WD - Amp/2
BD prism in PAL
Add power times 2/3
AREDS 2
Added copper to prevent copper deficient anemia that can be caused by excess zinc
Rod cone recovery time
After being bleached Cones = 10 min Rods = 35 min
Which of the following should be included in your patient education in regards to the use of topical ophthalmic medications in pregnant women?
After drop instillation, nasolacrimal compression and temporary punctual occlusion should be performed to minimize systemic drug absorption. As a general rule, if a medication is absolutely necessary, the lowest dosage for the least amount of time should be utilized. Certain anti-infectives such as gentamicin, erythromycin, and acyclovir, as well as anti-histamines are non-teratogenic and may be safely used as needed during pregnancy.
When to do BW on idiopathic uveitis?
After the 2nd recurrence
Terson syndrome
Aka shaken baby syndrome Vitreous hemorrhage + subarachnoid hemorrhage
Anton's syndrome
Aka visual anosognosia; denial of vision loss in patients with blindness (usually cortical/occipital lobe disease)
Seborrheic dermatitis
Along the scalp
Sulfa allergy
Also allergic to BAK and sodium sulfite
Who should NOT be dilated?
Although very rarely encountered, patients with an iris-fixed intraocular lens may not be dilated as this may cause dislocation of the lens. A characteristic finding associated with this type of lens is that the implant induces a square pupil. A patient with a plateau iris is rarely encountered. However, dilation of this patient will cause the iris root to block the trabecular meshwork leading to angle closure. A patient with a subluxated lens should not be dilated as this may cause the lens to be dislocated into the anterior chamber. Once in the anterior chamber, the lens may block the trabecular meshwork, leading to the development of glaucoma.
What are oscillations in the B wave of an ERG due to?
Amacrine cell responses
Meds and systemic diseases that cause whorl keratopathy?
Amiodarone Chlorpromazine Chloroquine Indomethacin Tamoxifen Fabry's disease
Primary structures of the limbic system + purpose of limbic system
Amygdala, hippocampus and regions of the septal area, and the limbal cortex which includes the hypothalamus, the cingulate gyrus, and the fornix Responsible for governing many of our emotions and feelings of motivation, especially those that deal with survival.
Ocular findings associated with Alzheimer's disease
Amyloid deposits on/in the crystalline lens Thinner nerve fiber layer Increased optic cupping
aponeurotic ptosis
An aponeurotic ptosis is caused by a defect in the levator aponeurosis caused by dehiscence, dis-insertion, or stretching (which can be due to normal aging changes) or by repetitive trauma in patients who constantly rub their eyes, wear gas-permeable contact lenses, or have undergone previous intraocular surgery. This abnormality restricts the transmission of force from a normal levator muscle to the upper eyelid. Common observable signs of an aponeurotic ptosis include the presence of a high eyelid crease, good levator function, and a moderate degree of ptosis (3 to 4mm) that may worsen in downgaze.
Loteprednol
An inactive metabolite of prednisolone
A 12-year old male is sitting in your waiting room while his mother undergoes her annual eye exam. While waiting, he eats a candy bar containing peanuts, and, as luck would have it, he is deathly allergic to nuts. To counter anaphylactic shock, what would be the BEST course of action?
Anaphylactic shock is defined as a severe, multi-system, type I hypersensitive, acute allergic reaction that may be life-threatening. Signs of an allergic reaction include tingling, itching, hives, swelling of lips and tongue, constriction of the airway, vasodilation, myocardial depression, and a decrease in blood pressure. The EpiPen is injected intramuscularly to the upper lateral thigh to ensure rapid delivery. Epinephrine (Adrenaline) activates both alpha and beta adrenergic receptors causing an increase in peripheral vascular resistance and allowing for an increase in blood pressure and coronary artery perfusion. Adrenaline also serves to reverse vasodilation and decrease urticaria and angioedema. For severe, life-threatening reactions, Benadryl (diphenhydramine) will not work quickly enough. Topical antihistamines have little if any systemic absorption and therefore will not be effective in counteracting the anaphylaxis. While oral steroids may be useful in the post-management of anaphylactic shock, they will not yield the desired immediate response.
Losartan = what drug type
Angiotensin receptor antagonist (NOT an ACE inhibitor) prevents ang2 from binding to its receptor => less vasoconstriction lower BP
The majority of glucose supplied to the cornea comes from
Aqueous humor
Falsely lowered A1c
Anything that shortens the lifespan of a cell. Hemolytic anemia, chronic kidney or liver disease, pregnancy, rheumatoid arthritis
What happens when a contact lens warps
Apical alignment stays the *same* Toricity will decrease by the amount of warpage in the same axis
How does RGP warping affect fit/OR?
Apical relationship will not change (average base curve will remain the same) Amount of toricity present when analyzing the fitting relationship will change; the toricity will *decrease* by the amount of warpage.
Ideal injection site for fluorescein angiography
Antecubital vein
Drugs and dry eye
Anti HTN, anti histamines, accutane and contraceptives
Common drugs that can lead to mydriasis that shouldn't be used in narrow angles?
Anti-histamines Dopamine agonists (ADHD, anti-parkinson's)
Which of the following classes of medications MOST commonly leads to the development of Stevens-Johnson syndrome? Non-steroidal anti-inflammatories Antibiotics Analgesics Corticosteroids Antivirals
Antibiotics
The denial of vision loss in patients with blindness is known as which of the following phenomenon? Charles Bonnet syndrome Anton's syndrome Blindsight Hysteria Your Answer Malingering
Anton's syndrome
Falsely elevated A1C
Any process that lengthens the life of a blood cell. Iron deficiency anemia, aplastic anemia, alcoholism, hyperbilirubinemia
How does GP center thickness change with changing OAD/BC?
As OAD increases or BC becomes steeper, thickness should increase
Granit-Harper law
As the log of the area of the stimulus is increased, the critical flicker fusion frequency also increases accordingly Peripheral retina is more sensitive to flicker: The chances of perceiving flicker are greater for a larger stimulus for a given modulation and beacuse peripheral retina has increased summation, a larger stimulus will take up more area of the retina, increasing the chances of detection
Normal tension GLC
Asians, Japanese most. Raynaud's phenomenon (peripheral vasospasm.) Higher propensity for disc hemes. VF defects have a tendency to be more central
What is high homocysteine associated with? What vitamin can lower these levels?
Assoc w/ premature atherosclerosis, thrombophlebitis complications Can be reduced by Vit B - but risk of CV disease doesn't go down
Pretibial myxedema
Associated with Grave's and Hashimoto's. Waxy discolored raised plaques. Biopsy will reveal mucin in mid to lower layers of dermis and is an accumulation of GAG's (HA.)
Myerson's sign
Associated with Parkinson's disease Failure to inhibit facial reflex when tapped between the eyes
Dissociated vertical deviation
Associated with infantile strab. Up drift of eye with excyclotorsion
Eyelid separation
At 6 months of gestation
Phacoanaphylactic uveitis
Autoimmune reaction secondary to proteins that have leaked from a lens with a ruptured capsule
Which classification of microorganism can synthesize its own food from inorganic sources? Prototrophs Autotrophs Heterotrophs Auxotrophs
Autotrophs
What is overall refractive state of the eye is determined by?
Axial length (averages 24mm in length) Anterior camber depth (averages 3.4mm) Corneal power (mean, 43 diopters) Crystalline lens power (mean, 21 diopters)
Craniopharyngiomas
From above the chiasm, **** with superior nasal fibers thus creating a bitemporal VF defect that is more dense inferiorly.
You receive a pair of glasses back from your fabrication lab that measures -1.25 -0.25 x 030. The original order was -1.25 -0.25 x 018. Before contacting your patient to let them know their glasses are ready for pick-up you check ANSI standards to see if this is within tolerance. According to ANSI standards, what is the tolerance for error in cylinder axis for this prescription? Axis may deviate up to 14 degrees Axis may deviate up to 18 degrees Axis may deviate up to 7 degrees Axis may deviate up to 3 degrees Axis may deviate up to 5 degrees
Axis may deviate up to 14 degrees
MOA of albuterol, salmeterol & metaproterenol
B agonists attach to B2 receptors on bronchioles => dilation salmeterol = long acting (not sure about others) (they also hit B1 receptors, but those are in the heart)
role of B vs. T cells? what are plasma cells?
B cells target EXTRAcell toxins or circulating pathogens in tissue/fluids plasma cells = B cells that secrete ABs T cells inactivate/attack INTRACELL pathogens, organ transplants or tumor cells
According to the American National Standards Institute (ANSI), what marking must be seen on the frame in order for it to qualify as a safety frame? A) The letter 'V' permanently etched onto the lens B) 'Z87-2' and the manufacturer's mark on the front of the frame and on both temples C) The letter 'S' etched onto the front of the frame and both temples D) A 'plus' mark (+) etched onto the periphery of the lens
B) 'Z87-2' and the manufacturer's mark on the front of the frame and on both temples
A 42-year old construction worker presents to you with a history of getting plaster in his right eye. He complains of pain, foreign body sensation, and photophobia. His acuity is reduced in that eye to 20/50 with a normal pupillary response. What type of chemical trauma did the worker experience, and what would be your first therapeutic intervention? A) Thermal burn and lavage eye with balanced saline solution for 30 minutes B) Alkali burn and lavage eye with balanced saline solution for 30 minutes C) Ultraviolet (UV) burn and lavage eye with balanced saline solution for 30 minutes D) Acid burn and lavage eye with balanced saline solution for 30 minutes
B) Alkali burn and lavage eye with balanced saline solution for 30 minutes
A 10-year old child presents in your office with a unilateral follicular conjunctivitis along with ipsilateral adenopathy. You correctly diagnose oculoglandular syndrome. Because it is the most common etiology, which of the following causes are you MOST likely to suspect? A) Measles B) Cat-scratch disease C) Coccidioidomycosis D) Diabetes E) Toxoplasmosis
B) Cat-scratch disease
You are providing follow-up care for a patient prescribed a low Dk soft contact lens worn on an extended wear basis. When would you most likely observe striae? A) In the evening after one week of seven day extended wear B) In the early morning after the first night of overnight wear C) In the evening after six months of seven day extended wear D) In the evening prior to the second night of overnight wear
B) In the early morning after the first night of overnight wear Striae are an acute response due to insufficient oxygen.
Fatty acid synthesis is activated during which of the following situations? A) Decreased levels of citrate and glucagon, increased levels of insulin B) Increased levels of citrate and insulin, decreased levels of glucagon C) Decreased levels of citrate and insulin, increased levels of glucagon D) Increased levels of citrate and glucagon, decreased levels of insulin E) Increased levels of citrate, decreased levels of glucagon and insulin F) Decreased levels of citrate, increased levels of glucagon and insulin
B) Increased levels of citrate and insulin, decreased levels of glucagon
The exit window of an optical system can be described by which of the following statements? A) The image of the field stop through all preceding lenses B) The image of the field stop through all following lenses C) The image of the aperture stop through all following lenses D) The image of the aperture stop through all preceding lenses
B) The image of the field stop through all following lenses
A 24-year old female patient is seen at your office and reports that her eyes have been red for a few days. Biomicroscopy reveals bilateral diffuse superficial punctate keratitis (SPK) that stains with sodium fluorescein with no mucopurulent discharge. Based ONLY upon the corneal staining pattern, what is the MOST likely origin of her condition? A) Dry eyes B) Viral C) Foreign Body D) Bacterial
B) Viral
A positive catalase test indicates that a bacteria is capable of breaking down which of the following? A. Glucose B. Hydrogen peroxide C. Pyruvate D. Carbon dioxide
B. Catalase is an enzyme commonly found in organisms that are exposed to oxygen. Catalase breaks down hydrogen peroxide into oxygen and water. The catalase test is performed by applying a drop of hydrogen peroxide to a microscope slide. A colony of bacteria is then exposed to the hydrogen peroxide via an applicator stick. The presence of bubbles or froth yields a positive catalase test. Staphylococci and Micrococci are catalase-positive organisms. Campylobacter and Escherichia coli are catalase-negative organisms.
In addition to the meibomian glands which other accessory glands secrete oil? A. Moll and Krause B. Zeiss and Moll C. Zeiss and Wolfring D. Wolfring and Krause
B. The glands of Zeiss and Moll are accessory oil glands located on the lid margins adjacent to the base of the lash follicles. The lipid layer of the tear film is superficial and as such it is exposed to the environment protecting the aqueous layer from evaporation. The glands of Wolfring and Krause are located deep in the fornix of the eyelids and serve to secrete a portion of the aqueous layer of the tear film.
Many skin anomalies may mimic malignant lesions. Which of the following skin conditions has the HIGHEST risk of becoming malignant? A. Papilloma B. Actinic keratosis C. Cutaneous horn D. Seborrhoeic keratosis
B. Actinic keratosis is a precursor to squamous cell carcinoma and appears as scaly, dry skin that does not heal. People with skin that is of lighter pigmentation along with excessive exposure to ultraviolet light tend to be most at risk for development of this condition. Papillomas may take on various forms and may be viral or non-viral in origin. They can commonly be found on the eyelids or surrounding orbital skin. Viral warts tend to grow at an accelerated rate while non-viral papillomas are fairly slow to grow. Papillomas can mimic neoplastic growths so be sure to rule this out while watching carefully for color change, ulceration, lash loss, bleeding, and vascularization. Cutaneous horns or tags are also benign and are likely a form of papilloma but appear to involve more keratin. Treatment is similar to that of a papilloma. Seborrhoeic keratosis is more commonly seen in middle-aged and elderly persons. This benign, epidermal growth is quite superficial and does not extend into the dermis. It appears like a brown plaque that has been stuck onto someone's skin. The borders are very distinct and there may be some elevation. The lesions may be removed if the patient is concerned about cosmesis.
Many skin anomalies may mimic malignant lesions. Which of the following skin conditions has the HIGHEST risk of becoming malignant? A. Papilloma B. Actinic keratosis C. Cutaneous horn D. Seborrhoeic keratosis
B. Actinic keratosis Explanation Actinic keratosis is a precursor to squamous cell carcinoma and appears as scaly, dry skin that does not heal. People with skin that is of lighter pigmentation along with excessive exposure to ultraviolet light tend to be most at risk for development of this condition.
Antibiotic resistance that is rapidly spread within a population of bacteria is due to what mechanism? A.Binary fission B.Conjugation C.Transformation D.Budding
B. Conjugation Explanation Conjugation occurs between a donor (possesses a conjugative plasmid) and recipient bacteria. The donor bacterium initiates contact with the recipient via a sex pilus, allowing for cell-to-cell contact and transfer of DNA. The plasmids often contain genes that encode for toxin production, virulence factors, and antibiotic resistance. Genetic transformation is achieved by very few strains of bacteria and may only occur during certain phases of growth; therefore, rapid antibiotic resistance is not feasible. Budding and binary fission are means of reproduction but are not directly responsible for antibacterial resistance. Genes must have been transferred that code for resistance prior to budding and binary fission in order for the progeny to contain genes that allow for drug resistance.
Patients with a history of homocystinuria are MOST likely to experience crystalline lens subluxation in which of the following directions? A.Up and outward B.Down and inward C.Up and inward D.Down and outward
B. Down and inward Explanation: Common ocular sequelae that have been associated with a diagnosis of homocystinuria include ectopia lentis (bilateral crystalline lens subluxation), retinal detachment, and secondary glaucoma. In most cases of ectopia lentis, the lens is more likely to be displaced downward and inward in homocystinuria (as compared to upward and outward in Marfan's syndrome). Additionally, in homocystinuria, the lens zonules are markedly abnormal, the lens does not accommodate, and up to 1/3 of the cases of lens subluxation eventually completely dislocate into the vitreous or anterior chamber. Due to the severity of systemic and cardiovascular complications associated with homocystinuria (thrombosis and occlusion), patients presenting with ectopia lentis should be screened for this disease using the sodium nitroprusside test to measure homocysteine in the urine.
A positive catalase test indicates that a bacteria is capable of breaking down which of the following? A.Glucose B.Hydrogen peroxide C.Pyruvate D.Carbon dioxide
B. Hydrogen Peroxide Explanation Catalase is an enzyme commonly found in organisms that are exposed to oxygen. Catalase breaks down hydrogen peroxide into oxygen and water. The catalase test is performed by applying a drop of hydrogen peroxide to a microscope slide. A colony of bacteria is then exposed to the hydrogen peroxide via an applicator stick. The presence of bubbles or froth yields a positive catalase test. Staphylococci and Micrococci are catalase-positive organisms. Campylobacter and Escherichia coli are catalase-negative organisms.
which fibers would be medial in the LEFT optic tract A. ipsi IT & contra IN B. ipsi ST & contra SN
B. ST+SN superior fibers always go medial
In addition to the meibomian glands which other accessory glands secrete oil? A. Moll and Krause B. Zeiss and Moll C. Zeiss and Wolfring D. Wolfring and Krause
B. Zeiss and Moll Explanation The glands of Zeiss and Moll are accessory oil glands located on the lid margins adjacent to the base of the lash follicles. The lipid layer of the tear film is superficial and as such it is exposed to the environment protecting the aqueous layer from evaporation. The glands of Wolfring and Krause are located deep in the fornix of the eyelids and serve to secrete a portion of the aqueous layer of the tear film.
A patient with high myopia undergoes electroretinogram (ERG) testing. Which of the following results is MOST likely to be observed? A. An increased b-wave amplitude B. A decreased b-wave amplitude C. An abnormal a-and b-wave amplitude ratio D. An increased a-wave amplitude
B. a decreased B wave amplitude high myopes display decreases S, L and M cone B-wave amps. B-wave amp is adversely affected in pts with chorioretinal degen AW high myopia. higher myopia = lower B wave -doesn't happen in pts with mild-to-moderate myopia (B wave = emmetropes)
what best describes the physiology behind the second heart sound (dub, of the lub-dub) A. Opening of the tricuspid and mitral valves B. Closing of the tricuspid and mitral valves C. Aortic+pulmonary close D. Opening of the aortic and pulmonary valves
B. aortic + pulmonary closing opening of heart valves is slow & quiet - CAN'T HEAR THEM OPEN. lub/s1 = closure of mitral+tricuspid (aka the atrioventricular valves) dub/21 = closure of aortic+pulmonary (aka semilunar valves) DUB = post-ejection; valves closing to let ventricles fill again
Lyme tick carries what bacteria
B. burgdorferi
What drug can exacerbate MG sx?
Beta blockers
Vit A
Beta carotene
You are measuring the palpebral fissure height in a patient reporting drooping of his upper eyelid. Which of the following BEST describes the normal positioning of the upper and lower eyelids in comparison to the limbus? A.The upper lid normally rests about 1mm lower than the upper limbus, and the lower lid rests about 2mm above the lower limbus B.The upper lid normally rests about 2mm lower than the upper limbus, and the lower lid rests about 1mm above the lower limbus C.The upper lid normally rests about 1mm lower than the upper limbus, and the lower lid rests about 2mm lower than the lower limbus D.The upper lid normally rests about 2mm lower than the upper limbus, and the lower lid rests about 1mm lower than the lower limbus
B.The upper lid normally rests about 2mm lower than the upper limbus, and the lower lid rests about 1mm above the lower limbus Explanation The palpebral fissure height is a measurement of the distance between the upper and lower eyelid margins when the patient is looking in primary gaze. This particular measurement is typically less in males (7-10mm) as compared to females (8-12mm). The normal positioning of the upper and lower eyelids are as follows: the upper eyelid usually rests about 2mm below the superior limbus, while the lower eyelid position is typically 1mm above the lower limbus. A unilateral ptosis can be quantified by comparing these measurements to the contralateral eye. A ptosis up to 2mm may be graded as mild; a 3mm ptosis is considered moderate; a ptosis of 4mm or more is deemed severe. Another important measurement in evaluating a ptosis is the marginal-reflex distance (MRD). The MRD can be defined as the distance between the upper eyelid margin and the resultant corneal reflection caused by directing a patient's gaze at a penlight held by the examiner. This measurement is normally 4-4.5mm.
behcets is AW which HLA
B51
HLA's
B51 = Bechet's B27 = CRAP B29 = Birdshot B7 and DR2 = Histo
1st order neuron in visual pathway =
BP cells
Transformation
Bacteria takes up naked DNA from another bacteria
What is the Bonnet sign? What grade HTN retinopathy?
Banking of veins distal to the AV crossing Grade 3
Segment height compensation for prism
Base down prism = raise the seg height up Base up prism = lower the seg height down
*Retinal image* is displaced towards what part of the prism
Base of the prism
Reis buckler
Basement membrane and Bowman's are replaced by fibrous tissue
Histamine releasing WBC's
Basophils and mast cells
What happens when a SCL dehydrate?
Becomes more minus OAD decreases Thickness decreases BC steepens Index of refraction increases
Which of the following components of the AREDS I ocular vitamin formula used for dry age-related macular degeneration is contraindicated in smokers? Beta-carotene Zinc Vitamin E Copper Vitamin C
Beta-carotene Based upon research, there may be a link between increased risk of lung cancer and beta-carotene supplementation when used with smokers.
Which of the following beta blockers used to treat glaucoma is cardioselective
Betaxolol
Degenerative retonoschesis
Between OPL and INL. Can get a scotoma. Most commonly inferior temporal
When performing a sub-Tenon's injection, how should the bevel of the needle be positioned?
Bevel towards the globe A sub-Tenon's injection is typically reserved for the treatment of vitritis, posterior uveitis, and cystoid macular edema. Once the eye is adequately anesthetized, place the needle bevel side towards the globe, 2 to 3 mm from the inferotemporal fornix, and penetrate the bulbar conjunctiva making sure not to nick any of the subconjunctival vessels. Once through the conjunctiva, at the planned injection location, move the needle tip back and forth to safeguard against penetration of the sclera. Prior to injecting, withdraw the plunger to make sure that the tip of the needle is not located within a vessel. Once you are sure that the needle is in the proper location, complete the injection.
Which area of the extrastriate cortex is involved in the perception of motion?
Beyond the striate cortex, visual information is thought to split into two separate streams: the ventral (also known as the "what" or temporal stream), and the dorsal (also known as the "where" or parietal stream). V5, also known as the middle temporal cortex (or MT), is considered to be a part of the dorsal stream and is believed to code for motion. V4 and IT are a part of the ventral stream. V4 serves to play a role in processing color while IT is important in classifying complex shapes and form recognition such as faces. V1 is the primary visual cortex and is not considered a part of the extrastriate cortex.
Double segment glasses
Bifocal at top and bottom of the lens with distance in the middle The two segs are always separated by 13-14mm
Menstruation inhibitors
Blastocyst secretes human chorionic gonadotropin, HCG, which signals the corpus luteum to secrete progesterone and estrogen which inhibits menstruation
Osteogenesis imperfecta
Bone breaks, blue sclera and hearing loss at a young age
Presenting signs of NF1 v. NF2
Both present with neurofibromas; NF2 doesn't have cafe au lait spots or Lisch nodules as much NF-2 - development of non-malignant CN8 tumors
which 2 layers of cornea scar
Bowmans + stroma (recall - bowmans + endo are the only 2 that dont regen)
why less haze with LASIK than PRK
Bowmans is left intact in LASIK, ablated in PRK
What limits brightness into a system? Field of view?
Brightness - pupil Field of view - field stop
Which topical NSAID could potentially reduce IOP while the others do not directly affect it
Bromfenac (Xibrom)
Which of the following topical NSAIDS must be used with caution in a person who is allergic to medications that contain sulfa?
Bromfenac (preserved with BAK and sodium sulfite)
Characteristics of bronchitis v. emphysema
Bronchitis - increased body mass (decreased) Predominant sx is coughing (intermittent) Large quantities of sputum (rare) Dyspnea in exercise only (predominant sx) More respiratory infections
What are C and D waves in an ERG created by?
C - RPE D - off-bipolar cells
If a thin lens with an index of 1.5 has a dioptric power of +4.00 in air, what is its power if placed in water? A) +1.18 diopters B) +11.76 diopters C) +1.36 diopters D) +4.00 diopters
C) +1.36 diopters
According to the Bohr Effect, which of the following statements is TRUE? A) A higher pH favors release of oxygen from hemoglobin into the tissues B) A higher pH favors release of oxygen from the tissues to hemoglobin C) A lower pH favors oxygen release from hemoglobin into the tissues D) A lower pH favors oxygen release from the tissues to hemoglobin
C) A lower pH favors oxygen release from hemoglobin into the tissues
Upon dilated fundus examination of your patient, you detect what appears to be elevation of the optic disc in both eyes. Which of the following observations would aid in distinguishing the presence of buried optic disc drusen from a diagnosis of optic disc edema? A) Spontaneous venous pulsation is usually absent in patients with optic disc drusen B) Vessels coursing the surface of the optic disc are usually obscured in patients with optic disc drusen C) Anomalous vascular patterns commonly occur in association with the presence of optic disc drusen D) Hyperemia of the disc is typically present in patients with optic disc drusen
C) Anomalous vascular patterns commonly occur in association with the presence of optic disc drusen
A patient walks into your office with a mild corneal abrasion, what is the correct healing sequence? A) Hemidesmosome formation between basal cells > basal cells at the wound margin flatten and spread > mitosis of cells surrounding wound area > attachment of cells via fibronectin and laminin B) Basal cells at the wound margin flatten and spread > attachment of cells via fibronectin and laminin > mitosis of cells surrounding wound area > hemisdesmosome formation between basal cells C) Basal cells at the wound margin flatten and spread > mitosis of cells surrounding wound area > attachment of cells via fibronectin and laminin > hemidesmosome formation between basal cells D) Mitosis of cells surrounding wound area > attachment of cells via fibrinectin and laminin > hemidesmosome formation between basal cells > basal cells at the wound margin flatten and spread
C) Basal cells at the wound margin flatten and spread > mitosis of cells surrounding wound area > attachment of cells via fibronectin and laminin > hemidesmosome formation between basal cells
Glycolysis occurs at which location within a eukaryotic cell? A) Nucleus B) Cellular membrane C) Cytosol D) Mitochondrion E) Endoplasmic Reticulum
C) Cytosol
How is the temporal modulation transfer function expected to change in a person with early glaucoma not yet manifesting any defects on visual field testing? A) Decreased sensitivity to low and moderate frequencies B) Decreased sensitivity to moderate frequencies only C) Decreased sensitivity to moderate and high temporal frequencies D) Decreased sensitivity to low temporal frequencies only
C) Decreased sensitivity to moderate and high temporal frequencies
Dietary triglycerides are metabolized primarily by which organ of the body? A) Kidney B) Liver and gall bladder C) Intestine D) Stomach
C) Intestine
A newborn presenting with symptoms of ophthalmia neonatorum 3 days after birth is MOST likely infected with which of the following organisms? A) Haemophilus influenza B) Herpes Simplex Virus C) Neisseria gonorrhoeae D) Streptococcus pneumonia E) Chlamydia trachomatis F) Staphylococcus aureus
C) Neisseria gonorrhoeae
Which of the lipoproteins is the largest? Has the most amount of protein?
Largest - chylomicrons Most protein (and densest) - HDL
During the generation of a dark adaptation curve, the stimulus is changed from 420 nm to 650 nm. How will the resulting dark adaptation curve vary from the original? A) The portion of the curve that depicts the rod adaptation will be much steeper B) The portion of the curve that depicts the cone adaptation will be longer C) The curve will lack a rod-cone break D) The overall time period for dark adaptation will be considerably longer
C) The curve will lack a rod-cone break
Which of the following binocular balancing tests CANNOT be performed on a patient with visual acuities of 20/50 OD and 20/50 OS? A) Bichrome balance test B) Prism dissociation balance test C) There is no restriction upon which binocular balance test may be utilized on this patient D) Alternating occlusion balance test
C) There is no restriction upon which binocular balance test may be utilized on this patient As long as they have equal acuities in both eyes, you can chose any binoc balance test. --If unequal, use bichrome balance test.
Oral acyclovir is most effective for patients presenting with eyelid findings associated with herpes zoster if administered within which of the following periods following the onset of the disease? A. 7-10 days B. 24 hours C. 72 hours D. 10-12 hours E. 4-5 days
C. Oral acyclovir is the mainstay of therapy for patients diagnosed with herpes zoster ophthalmicus. This systemic treatment is maximally beneficial of it is initiated within 72 hours from the onset of the disease (usually the appearance of eyelid lesions). The use of oral acyclovir typically results in quick resolution of skin vesicles, decreases the amount of pain the patient experiences, and reduces the duration of viral shedding and appearance of new lesions. Acyclovir has also been shown to significantly reduce the incidence of ocular findings such as episcleritis, keratitis, and iritis. The recommended dosage is 800mg orally 5 times per day for 7-10 days.
Congenital cataracts can be caused by a viral infection of the mother with rubella virus (German measles) during development of the primary lens fibers. At which time period in embryonic development can infection cause congenital cataracts? A. 2nd trimester B. Conception C. 1st trimester D. 3rd trimester E. Post-delivery
C. The developing lens is susceptible to rubella virus when the lens fibers are forming, which occurs around weeks 4-7 of gestation. Earlier infection will occur prior to lens fiber development, and the lens is resistant to later infection because the virus is unable to penetrate the lens capsule. The fetus is most susceptible to lenticular damage during the first trimester. Contraction of the rubella virus will cause the greatest amount of damage during this time period. Congenital cataracts are usually detectable at birth but may be seen later because the virus can persist in the lens.
The lymphatic system serves many important roles in the human body. The lateral portion of the eyelid lymphatics drain into which of the following structures? A. The conjunctiva B. The puncta C. The pre-auricular lymph node D. The submandibular lymph node
C. The lateral 2/3 of the upper lid and the lateral 1/3 of the lower lid lymphatics drain into the pre-auricular lymph node located directly in front of the ear. The medial 1/3 of the upper eye lid and the medial 2/3 of the lower lid lymphatics drain into the submandibular node located just under the jaw-line. Therefore, it is very important to evaluate these two nodes separately, especially when a condition of viral etiology is suspected.
Oral acyclovir is most effective for patients presenting with eyelid findings associated with herpes zoster if administered within which of the following periods following the onset of the disease? A. 7-10 days B. 24 hours C. 72 hours D. 10-12 hours E. 4-5 days
C. 72 Hours Explanation Oral acyclovir is the mainstay of therapy for patients diagnosed with herpes zoster ophthalmicus. This systemic treatment is maximally beneficial of it is initiated within 72 hours from the onset of the disease (usually the appearance of eyelid lesions). The use of oral acyclovir typically results in quick resolution of skin vesicles, decreases the amount of pain the patient experiences, and reduces the duration of viral shedding and appearance of new lesions. Acyclovir has also been shown to significantly reduce the incidence of ocular findings such as episcleritis, keratitis, and iritis. The recommended dosage is 800mg orally 5 times per day for 7-10 days.
What is chrysiasis?
Chrysiasis occurs secondary to the deposition of gold in the skin, lens, and cornea, causing a gray discoloration of the skin and brown/gold deposits in the deep stroma of the cornea [gold salts are used to tx RA if other meds have failed]
A chiasmal lesion or mass, such as a pituitary tumor, generally causes what type of visual field defect? A. Left homonymous hemianopsia B. Right homonymous hemianopsia C. Bitemporal hemianopsia D. Binasal heminopsia
C. Bitemporal hemianopsia Explanation The center of the chiasm contains axons of decussating ganglion cells that originate from the nasal retinas, which process temporal visual field information. The lateral portion of the chiasm is comprised of the axons of the temporal aspect of the retinas, which do not cross over. Lesions most commonly occur in the central portion of the chiasm and not the lateral aspects. Any central chiasmal mass or lesion will cause a bitemporal visual field defect that respects the vertical midline.
Which of the following correctly describes the movement of the eyelids and globe on closure during a REGULAR blink? A. Upper and lower lids close medial to lateral direction, globe moves posteriorly B. Upper and lower lids close lateral to medial direction, globe moves forward C. Upper and lower lids close lateral to medial direction, globe moves posteriorly D. Upper and lower lids close medial to lateral direction, globe moves forward
C. Correct answer Upper and lower lids close lateral to medial direction, globe moves posteriorly zipper lateral to medial globe moves BACK (most likely defensive)
Purkinje images are caused by reflections of objects on the cornea and lens. Which of the four images moves forward with accommodation? A.I B.II C.III D.IV
C. III Explanation There are four Purkinje images. The first image is caused by reflection from the anterior corneal surface and is the brightest of the images. The first image is roughly the same size as the object. The second Purkinje image is formed by the posterior surface of the cornea and almost coincides with the first Purkinje image. The third Purkinje image is the largest and is caused by reflection off of the anterior plane of the crystalline lens. The fourth Purkinje image is the smallest and is inverted, formed by reflection off of the posterior surface of the lens. During the process of accommodation the anterior surface of the lens moves forward. The image that is reflected off of this surface is Purkinje III. Purkinje image III will be seen to move forward during accommodation.
which of the following would not be a cause of a non-rheg RD? A. sickle cell B. ROP C. PVD D. diabetic retinopathy
C. PVD PVD = tractional tears all the other 3 cause neo which is non-rheg
Clock dial axis refinement
Can be refined within 7.5 degrees because if like the 2-8 line is clearest, followed by the 1-7 line and the 3-9 line is worse than the 1-7, we know that the axis is a quarter between the 2-8 line and the 1-7 line, with the axis being closer to the 2-8 line
Lower order aberrations
Can be corrected be lenses or surgery
Blindsight
Can see but they act like they are blind. As opposed to Anton's where they have vision loss but deny it
The lymphatic system serves many important roles in the human body. The lateral portion of the eyelid lymphatics drain into which of the following structures? A.The conjunctiva B.The puncta C.The pre-auricular lymph node D.The submandibular lymph node
C.The pre-auricular lymph node Explanation The lateral 2/3 of the upper lid and the lateral 1/3 of the lower lid lymphatics drain into the pre-auricular lymph node located directly in front of the ear. The medial 1/3 of the upper eye lid and the medial 2/3 of the lower lid lymphatics drain into the submandibular node located just under the jaw-line. Therefore, it is very important to evaluate these two nodes separately, especially when a condition of viral etiology is suspected.
whorl keratopathy drugs mnemonic
CHATI chloroquine/Hydroxy Amiodarone Tamoxifen Indomethacin
what can cause increased organ pressure? result?
CHF, liver cirrhosis, vein obstruction or compression => EDEMA (non-inflammatory)
what lesion = most common precursor for CONJ squamous cell
CIN (gelatinous mass with neo) -rose stains tumor margins most common overall precursor for squamous = actinic keratosis
which CNs decussate (ie. lesion will be in contralateral nucleus)
CN 4 (entire nerve) CN 3 - SR fibers only
Which of the following medications/supplements, if used in high doses, may produce crystalline retinopathy, whereby bilateral, fine, yellow deposits can be observed in the inner layers of the retina? Thioridazine Canthaxanthin Hydroxychloroquine Chloroquine Chlorpromazine
Canthaxanthin [sun tanning pills]
bilateral, fine, yellow crystalline deposits in inner retinal layers =
Canthaxanthin in high doses/long term (carotenoid supp, tanning) tiny yellow glistening deposits in symmetric donut
Captopril MOA Verapamil MOA
Captopril = ACE inhibitor Verapamil = Ca blocker
Job of LDL?
Carries cholesterol to cells
Bartonella henselae
Cat scratch disease
10-year old child presents w/ unilateral follicular conjunctivitis and ipsilateral adenopathy (aka lymphadenopathy). You correctly diagnose oculoglandular syndrome. Because it is the most common etiology, which of the following causes are you MOST likely to suspect?
Cat-scratch disease -- Oculoglandular syndrome can be caused by a myriad of organisms and presents as a unilateral follicular conjunctivitis along with lymphadenopathy on the same side as the affected eye. Based solely upon the age of the child, one would first assume cat-scratch disease, which is the most common cause of oculoglandular syndrome. This assumption would be verified by asking if the child had recently been scratched by a cat and by performing the Hanger-Rose skin test for confirmation.
What is the leading cause of blindness in the adult population worldwide
Cataracts
3 and 9 staining
Caused by EXCESSIVE edge lift. To decrease the edge lift, increase the OAD, steepen the peripheral edge curve or decrease the edge thickness
Glial cells is responsible in central and peripheral nervous system with myelin sheath?
Central - Oligodendrocytes (wrap multiple neurons) Peripheral - Schwann cells (individually wrap neurons)
PMD
Central corneal thickness remains normal while the cornea will thin in the periphery
Types of pathways of info present in the retina?
Centripetal/feed-forward - PRs to bipolar and ganglion Lateral processing pathway - amacrine and horizontal cells Centrifugal pathway - ganglion to PRs via interplexiform
Acephalgic migraines
Characterized by the presence of visual disturbances but without the development of a headache
Lactoferrin
Chemical defense. Binds iron which bacteria need
Population with highest prevalence of angle-closure glaucoma?
Chinese
Which of the following is the dermatological term that is known for an increase in pigmentation commonly seen around the eyes and cheeks of pregnant women?
Chloasma This pigmentary change in the skin of the face tends to fade slowly postpartum
Cumulative dose of chloroquine and hydroxychloroquine needed to get retinal toxicity?
Chloroquine - 300 grams Hydroxy - 400 mg/day taken over a period of months to years, or a cumulative dose of 1,000 grams
Job of HDL
Cholesterol from peripheral tissues to liver for breakdown + excretion in bile
Job of LDL
Cholesterol to various cells
Dalen-Fuchs nodules
Chorioretinal lesions that represent epitheloid cells between Bruch's and RPE Assoc w/ sympathetic ophthalmia, Vogt-Koyanagi-Harada disease
Lung tumors will likely metastasize to what part of the eye
Choroid (Uvea)
Most common cause of secondary cataract?
Chronic anterior uveitis
Most common cause of trichiasis
Chronic bleph
Most common cause of trichiasis
Chronic blepharitis
Philadelphia chromosome is highly sensitive to
Chronic myelogenous leukemia
During accommodation
Ciliary muscle contracts and zonular tension relaxes Diameter of the lens decreases Thickness of the lens increases Anterior surface of the lens moves anteriorly Posterior surface of the lens moves posteriorly Thickness of the lens *nucleus* increases Increase in curvature of the anterior and posterior lens surfaces
Which of the following groups is NOT classified as association fibers which are used to support and brace the lenticular zonules? Ciliocapsular Interciliary Orbiculociliary Circular
Ciliocapsular
What does the pineal gland do?
Circadian rhythms
Blinking
Close twice as fast as they open. Normal blink rate is 12-15 blinks a minute
What is the proper term for the situation in which both alleles for a trait are expressed? Co-dominance Heterozygous Independent assortment Pleiotropy
Co-dominance
Satler's veil phenomenon
Colored fringes are seen around bright lights due to corneal edema (Basal cells act as diffraction gratings)
whats Sattler's Veil
Colored fringes seen around bright lights due to corneal edema swollen cornea => basal cells scatter light
3rd order aberrations
Coma and trefoil
Blephamide
Combination of sulfacetamide and prednisolone
Primary congenital glaucoma
Common symptoms include photophobia, epiphora, and blepharospasm. Ocular signs include larger overall corneal diameter at birth, corneal clouding, Haab's striae, and abnormal optic nerve head(s).
Blepharoclonus
Commonly seen in 5-10 yo, frequently no cause can be determined, self-limiting . Increased blink rate (the most common form) or increased duration of lid closure. R/o any possible external cause (ex - irritation to a portion of the anterior segment)
Reverse swinging flashlight
Comparing the direct response of a reactive pupil with the consensual response of the same pupil. Good for testing for pharmacological mydriasis
Epiblepharon
Congenital horizontal fold of skin near the upper or lower eyelids that leads to a redirection of the lashes into a vertical position where they may touch the globe
Nevus of Ota
Congenital increased pigmentation of periorbital skin + uveal tract Need to monitor for malignancy, glaucoma (pigment can impede flow of aqueous through TM)
What are common side effects of morphine
Constipation Nausea Respiratory depression *increases parasympathetic activity*
Causes of cicatricial ectropion
Contraction of scar tissue following injury (burns or lacerations) or surgery to the eyelid
What does the midbrain do?
Coordinate visual, auditory, and tactile input
Describe corneal dystrophies vs. degenerations
Corneal dystrophies: usually bilateral, symmetrical, inherited, affect only 1 layer, rarely a/w systemic disease Corneal degenerations: usually unilateral, affect periphery, 2ndary to infection/insult/trauma causing breakdown of tissue
What layer of the cornea is most likely to result in graft rejection after a penetrating keratoplasty
Corneal endothelium
What is the primary ocular concern in patients diagnosed with Bell's palsy
Corneal exposure
Prolate vs oblate
Corneas are normally prolate, they flatten in the periphery. Oblate is flatter in the center and steeper in the corner and can be caused by lasik, RK and ortho K
Which organism is MOST commonly associated with the formation of "true" membranous conjunctivitis?
Corynebacterium diphtheriae can also be caused by strep hemolyticus, pneumonia, N gonorrheae, aureus, H aegypticus, E coli, adenovirus, HSV but membs are more or less synonymous with diptheric cjvitis
parotiditis is often seen with what infection
mumps (swelling or infection of salivary glands)
The linear field of view of a direct ophthalmoscope (DO) can be increased the MOST via which of the following mechanisms? A) Increasing the size of the doctor's pupil B) Increasing the brightness of the light source C) Increasing the distance between the aperture and the patient's pupil D) Increasing the size of the patient's pupil
D) Increasing the size of the patient's pupil
Coenzyme Q, vitamins A, D, E and K, and cholesterol are all derived from which of the following lipids? A) Triglycerides B) Phospholipids C) Sphingolipids D) Isoprenes and terpenes
D) Isoprenes and terpenes
An amphipathic molecule will react in what manner when exposed to water? A) It will completely dissolve B) It will form a gas C) It will combust D) It will form micelles
D) It will form micelles
Cryptococcus neoformans
Cryptococcosis (fungal infection)
What causes cryptococcosis?
Cryptococcus neoformans
The only structure in the eye that is isolated from the immune system (*antigenic*)
Crystalline lens
Proteins found in the lens
Crystalline proteins - alpha (heaviest), beta (most numerous), gamma Albuminoid proteins - not water-sol
Which of the following regarding zone of inhibition is TRUE? A) Allows for the determination of which type of media promotes the proliferation of a specific bacteria B) The larger the zone of inhibition, the greater the degree of resistance displayed by the organism C) Allows one to quantify the number of plaque-forming units (PFU) D) Denotes the sensitivity of an organism to an antibiotic
D) Denotes the sensitivity of an organism to an antibiotic
Which of the following is an example of specific immunity in the eye? A) Secretion of specific antibodies into the tear film by T- lymphocytes B) Interferon production in response to viral infection C) Regular turnover of corneal epithelial cells D) Destruction of virally infected conjunctival cells by cytotoxic T- lymphocytes E) Flushing of the eye by tears when the eye is traumatized
D) Destruction of virally infected conjunctival cells by cytotoxic T- lymphocytes Specific immunity indicates a response that is specific to the offending agent and requires recognition of that agent by the immune system.
In patients diagnosed with obstructive lung disease, which of the following is TRUE in regards to the calculated FEV1 / FVC ratio? A) Both FEV1 and FVC are equally elevated; therefore, ratio is normal B) FEV1 / FVC ratio is elevated C) Both FEV1 and FVC are equally reduced; therefore, ratio is normal D) FEV1 / FVC ratio is reduced
D) FEV1 / FVC ratio is reduced The ratio of FEV1 to FVC (forced expiratory volume over one second to forced vital capacity) is used in the diagnosis of obstructive and/or restrictive lung disease.
You are fitting a 6 year-old with a progressive addition lens (PALs) due to a binocular vision condition. Which of the following adjustments to the fitting height is MOST appropriate to ensure that he will actually look through the add power when doing near tasks? A) Fitting height should be about 2mm lower than normal B) No adjustment needs to be made C) Fitting height should be about 2mm higher than normal D) Fitting height should be about 4mm higher than normal E) Fitting height should be about 4mm lower than normal
D) Fitting height should be about 4mm higher than normal
What immunosuppressant is commonly used to prevent corneal graft rejection
Cyclosporin A
Primary drug to prevent corneal graft rejection?
Cyclosporine A
Cysticercus cellulosae
Cysticercosis (infection that results in cysts throughout the body)
Glycolysis occurs at which location within a eukaryotic cell?
Cytosol -- "Glycol occurs in the cytosol!" -- Glycolysis is an important metabolic pathway that breaks down glucose into pyruvate. Then, pyruvate can either be converted anaerobically into lactate or undergo oxidative phosphorylation yielding 36 moles of ATP.
What following muscles of the face are responsible for the closure of the eyelids
Corrugator Procerus Orbicularis oculi defective = blepharospasm
which is NOT true regarding Salzmann's nodular degen? A. pts rarely have Sx B. common in trachoma C. common in interstitial keratitis D. usually bilateral
D it's usually uni
When a chromophore absorbs a photon of light, which of the following changes occurs? A) all-trans-retinal isomerizes to 11-cis-retinal B) 11-trans-retinal isomerizes to 11-cis-retinal C) 11-cis-retinal isomerizes to 11-trans-retinal D) 11-cis-retinal isomerizes to all-trans-retinal E) all-cis-retinal isomerizes to 11-trans-retinal F) 11-trans-retinal isomerizes to all-cis-retinal
D) 11-cis-retinal isomerizes to all-trans-retinal
What does angle recession of the eye refer to? A) A tear between the posterior aspect of the zonules and the lenticular equator B) A detachment between the ciliary body and the scleral spur C) A detachment between the iris root and the ciliary body Your Answer D) A tear between the longitudinal and circular muscle layers of the ciliary body
D) A tear between the longitudinal and circular muscle layers of the ciliary body
One of the conclusions of The Ocular Hypertension Treatment Study (OHTS) showed that 9.5% of untreated ocular hypertensives developed glaucomatous optic nerve head or visual field damage over the first 5 years of follow-up. What did the study conclude about those who were treated to at least a 20% decrease in intraocular pressure during that same follow-up period? A) Only 2.4 % of treated ocular hypertensives developed glaucomatous damage B) The same amount of treated and untreated ocular hypertensives developed glaucomatous damage C) None of the treated ocular hypertensives developed glaucomatous damage D) Only 4.4% of treated ocular hypertensives developed glaucomatous damage
D) Only 4.4% of treated ocular hypertensives developed glaucomatous damage
A 32-year old male is seen at your office and is in a fair amount of pain. He can barely open his right eye and reports that the pain began this morning when he first opened his eyes. His medical history is unremarkable, and he does not wear contact lenses. His ocular history is remarkable for a mild corneal abrasion of the right eye from a tree branch that occurred over a month ago but had since healed. Biomicroscopy (after instillation of a topical anesthetic) reveals an epithelial defect 1.5mm wide and 1.0mm long that stains with sodium fluorescein. There is no anterior chamber reaction and no visible discharge. What is the MOST appropriate diagnosis? A) Corneal ulcer (microbial keratitis) B) Epithelial basement membrane dystrophy C) Corneal abrasion D) Recurrent corneal abrasion
D) Recurrent corneal abrasion
Alpha helices and beta sheets are considered which level of protein structure? A) Quaternary B) Primary C) Tertiary D) Secondary
D) Secondary
While performing streak retinoscopy on a 6 year-old patient at a working distance of 50cm, you observe with-motion with no lenses in place. Which of the following refractive errors can you deduce that this patient is MOST likely to possess? A) Hyperopia B) Astigmatism C) Myopia D) You cannot conclude the type of refractive error based upon the above findings
D) You cannot conclude the type of refractive error based upon the above findings
A patient is using a stand magnifier of +16D with a +2.00 add. If the distance separating the two lenses is 25 cm what is the equivalent power of this combination? A. 26D B. 22D C. 18D D. 10D
D. De= D1+D2 -tD1D2 where De=equivalent power;D1=power of magnifier;D2=power add;t=separation in meters between the lenses De = (16+2) - 0.25(16)(2) De= 18-8 = 10D 18D- incorrect answer -would come up with this if added the stand magnifier power to the power of the add 22D -incorrect answer - would come up with this if added 16D for stand mag 2D for add and 4D for equivalent of 25cm. 26D - if added the 18 +8 in the De equation instead of subtracting
A patient with a high AC/A ratio (8/1) displays esophoria at a 6 m distance. Based on the AC/A ratio, how would you expect the phoria to change as the target is brought closer to the patient? A. Decrease in eso deviation B. Remain unchanged C. Increase in exo deviation D. Increase in eso deviation
D. The AC/A ratio denotes the amount of change to convergence resulting from a change in accommodation. If a patient possesses a high AC/A ratio (6/1 is considered the normal range), a one-diopter increase in accommodation will theoretically cause a greater increase in convergence. Regardless of the initial phoria, with decreasing viewing distance the phoria will become more eso (or less exo). The opposite holds true for a low AC/A ratio (less than 6/1); as the target gets closer, the resultant phoria becomes more exo or less eso.
A concerned father reports that one of his 12-month-old infant's eyes does not appear straight. You decide to perform the Hirschberg test to evaluate for strabismus. The corneal reflex of the right eye is centered, while the left reflex is displaced 0.5 mm superiorly relative to the center of the pupil. Angle Kappa (Lambda) is zero for each eye. What is the correct deviation and magnitude of the observed strabismus? A. Left hypotropia of 22 prism diopters B. Left hypertropia of 11 prism diopters C. Left hypertropia of 22 prism diopters D. Left hypotropia of 11 prism diopters
D. The Hirshberg test is performed at a distance of 50 cm. A penlight or transilluminator is held just below the doctor's preferred eye and the doctor then sits in front of the patient and directs the beam towards the patient's nose while the patient is instructed to fixate on the light. The position of the corneal reflexes relative to the center of the pupil is assessed in each eye. Superior displacement of the corneal reflex suggests hypotropia, while inferior displacement infers hypertropia. Each millimeter of displacement of the reflex from the center of the pupil equates to roughly 22 prism diopters of deviation.
A Galilean telescope has an ocular lens with a power of -32.00 D and an objective lens with a power of +8.00 D. What is the magnification provided by the telescope? A.256x B.8x C.0.25x D.4x
D. 4x Explanation To calculate the magnification (M) of a telescope divide the power of the ocular lens (Doc) by the power of the objective lens (Dobj): M=-Doc/Dobj. In the example above, M=-(-32 D)/8 D= 4x. The magnification of a Galilean telescope is positive due to the fact that its ocular has a minus powered lens. The magnification of an astronomical telescope is negative and therefore its image will be upside down.
Mucin balls
Generally seen in flat-fitting, EW SiHys; not a threat to vision or health; will pool fluorescein upon CL removal but won't stain To fix - steepen the BC, add re-wetting drops
A 42-year old patient reports that her right eye has been watery and she has mild pain, redness, and swelling in the lower medial canthal region. You suspect dacryocystitis as the cause of her symptoms. Which of the following procedures is NOT appropriate when further evaluating this possible diagnosis? A.Exophthalmometry B.Extraocular muscle motility C.Digital palpation of the medial canthal area D.Dilation and irrigation of the lacrimal system E.Gram stain and blood agar cultures of discharge
D. Dilation and irrigation of the lacrimal system Explanation The evaluation of a patient suspected of dacryocystitis should involve a detailed case history including a discussion of any previous episodes with similar symptoms, or the presence of any concomitant ear, nose, or throat irritation/infection. External examination of the patient should include the application of gentle pressure to the lacrimal sac region in order to attempt to express any discharge from the punctum; this should be done bilaterally. If any discharge can be recovered, a Gram stain or blood agar culture is helpful in determining the type of bacteria present. In addition to these tests, extraocular motility and evaluation for the presence of proptosis should be completed to rule out orbital cellulitis. In atypical, severe, or non-responding cases, a computed tomography scan (CT) should be considered. It is important to remember that probing, dilation, and/or irrigation of the lacrimal system should not be attempted during an acute infection of the lacrimal gland. This may cause the infection to spread to other areas such as the throat.
Gonorrhea v. chlamydia ophthalmia neonatorum?
Gonorrhea - 2-5 days post-partum (5-14 days) Hyperacute conjitis / mild-moderate conjitis Chlamydia is more common cause
Numerous reports have suggested that increased tear film osmolarity is a key consequence in dry eye. Although osmolarity is not easily measured in the clinical setting, tear osmolarity increases in most dry eye sub-types due to which of the following processes? A. In aqueous tear deficiency, the lacrimal gland produces more ionic species B. The lipid layer is altered in most dry eye states, leading to ion pairing C. Decreased capillary exchange leads to ionic bonding D. Loss of tear stability induces an increased evaporation rate, leading to increased osmolarity E. Reactive oxygen species are increased in the tears of most dry eye sub-types; this increases osmolarity F. Patients with dry eye tend to blink less than normals, leading to increased evaporation
D. Loss of tear stability induces an increased evaporation rate, leading to increased osmolarity Explanation Tear instability leads to greater evaporation and higher osmolarity through a mechanism of concentration of the remaining tears, since only the aqueous tear portion evaporates rather than the ionic species. Several studies have indicated that normal tear osmolarity is less than or equal to 300 Osm/L, with values exceeding 308 Osm/L indicating increased osmolarity. As a single measure, tear osmolarity has recently been found to correlate the best (r squared 0.55) to dry eye severity of several clinical tests in a large, multi-center study (Sullivan et al., IOVS 51:6125-6130, 2010).
Which of the following physical examination findings are found in an allergic individual? A. Hyperpigmentation of the inferior periorbital skin B. Lateral crease of the distal nose C. Lymphoproliferation of posterior oropharynx D. all of the above
D. all of the above hyperpig = "allergic shiners" - engorgement of superficial caps downstream of nasal inflam nasal crease from frequent rubbing due to pruritus lumph prolif = "cobblestoning" - from allergic rhinitis chornic inflam response
The ligaments that suspend the lens (zonules) are embryonically derived from what structure? A.The lens capsule B.The primary vitreous C.The lens epithelium D.The tertiary vitreous
D. The tertiary vitreous Explanation The zonules are attached to the posterior and anterior surfaces of the lens and connect to the pars plana of the ciliary body. The primary vitreous develops from weeks 3 through 9. The secondary vitreous then begins to form and condenses the primary vitreous forming Cloquet's canal. Developmentally, the tertiary vitreous is secreted last; the zonules are comprised of condensed tertiary vitreous.
You are fitting a toric soft contact lens to your patient's right eye. The patient's manifest refraction is -2.00 -1.50 X 095. You apply a -1.75 -1.25 X 085 diagnostic toric soft contact lens. It fits well, and the prism base down marking consistently locates halfway between the 6 o'clock and 7 o'clock hours. What axis should you order? A.70 degrees B.95 degrees C.100 degrees D.110 degrees E.80 degrees
D.110 degrees Explanation Applying LARS to compensate for lens rotation, since the lens is rotated to the Left, you would Add the amount of left rotation to the manifest refraction axis. Every hour on the clock dial would translate to 30 degrees rotation. In the above example, the lens is rotated to the doctor's left by 15 degrees (between the 6 and 7 o'clock hours). Add the amount of rotation (15 degrees) to the cylinder axis of the manifest refraction (95 degrees). This results in a cylinder axis order of 110 degrees.
What is the equivalent of a Reduced Snellen 20/50 optotype in metric notation (assuming a working distance of 40 cm)? A.0.67M B.0.5M C.2M D.1M
D.1M Explanation To convert from Reduced Snellen to metric notation one must divide the denominator by 50. In the above example 50/50 = 1M. To convert from Reduced Snellen to Printer's point, divide the denominator by 6. To convert from Printer's point to metric, divide by 8. To convert from Metric notation to Reduced Snellen, multiply by 50; this will give you the denominator of Reduced Snellen. A good rule of thumb is 1M = RS 20/50 = 8 point. See attached for conversion triangle.
What is the net overall moles of ATP produced by the electron transport chain (i.e. not including glycolysis)? A.2 moles of ATP B.30 moles of ATP C.6 moles of ATP D.34 moles of ATP E.38 moles of ATP
D.34 moles of ATP Explanation The electron transport chain yields a total of 34 moles of ATP. Glycolysis produces a total of 2 moles of ATP. The overall net of cellular respiration is 36 moles of ATP.
The circumlental space is created by an interval between which two structures? A.The anterior face of the lens and the posterior surface of the iris B.The posterior surface of the cornea and the anterior face of the iris C.The posterior face of the lens and the anterior vitreous D.The equator of the lens and the ciliary body
D.The equator of the lens and the ciliary body
daily life things that cause temporary decr IOP? incr?
DECREASE: Exercise, general anesthesia, alcohol consumption, and marijuana INCREASE: Transitioning from sitting to a lying down position, blinking, coughing, blepharospasm and tobacco usage
most common cause of filamentary keratopathy
DES any chronic inflam can cause them
The equation for adding thin lenses with some separation is as follows:
De = D1 + D2 - (t/n) x D1D2 if thickness is zero (lenses are placed in immediate succession) De = D1 + D2
Which 2 of the following anterior segment changes are MOST likely to occur during pregnancy?
Decrease in IOP and decrease in corneal sensitivity. The reduction in IOP is likely caused by an increase in the outflow facility of aqueous as a result of a combination of several factors, including an increase in uveoscleral outflow (due to hormonal changes), decreased episcleral venous pressure, and a decrease in the overall pressure in the upper extremities. For these reasons, there have been cases of pre-existing glaucoma that have actually improved during pregnancy.
What happens to muscle activity in the event of extremely hot temperatures?
Decrease in muscle activity
Pigmentary GLC
Deep anterior chambers that causes the iris to rub against the lens zonules
Meissner's corpuscles
Detect and adapt slowly to low-frequency vibrations
Area of goldmann tono
Determined to cancel out the surface tension of tear film and corneal elasticity. Typical diameter is 3.06 mm. So area is 7.3 mm squared
Given any two reflections (or any even number of reflections), the deviation of the reflection is dependent upon the angle between the two mirrors (as long as the angle is not equal to 90 degrees) but is not contingent upon the angle of incidence of the ray at the first mirror
Deviation = 360 - 2(theta)
What three conditions are commonly associated with Rubeosis iridis
Diabetes mellitus Central retinal vein occlusion Chronic retinal detachment
The anterior portion of the ciliary body which contains the ciliary processes is known as which of the following
Pars plicata
Which topical NSAID has the greatest potential to cause corneal melt
Diclofenac (Voltaren)
Job of chylomicrons
Dietary triglycerides from intestine --> adipose or liver
How does toxic keratitis stain?
Diffuse SPK
What med causes yellow/green tinge?
Digoxin
What is commonly associated with Fifth through Tenth-order aberrations
Dilated pupils
Foster-Kennedy syndrome
Disc edema one eye and optic atrophy the other eye. most commonly caused secondary to frontal lobe tumors and olfactory groove meningiomas
Point notation
Dived the denominator by 6, assuming a distance of 40 cm
How can you solve for point notation if given a Snellen fraction?
Divide Snellen denominator by 6 to get point notation
Lateral sulcus / Sylvian fissure
Divides the frontal and parietal lobes from the temporal lobe
Endophthamitis
Does not involve the sclera, panophthalmitis does
Optyl
Does not shrink but will expand with heat, so cut the lenses .6 - 1 mm larger than the frame size
Initial electron donor in ETC? Electron acceptor?
Donor - NADH, FADH2 Acceptor - oxygen
Trabeculectomy
Drainage bleb, alternate route, creates a fistula between angle and sub tenon's space
which refractive procedure has highest incidence of: dry eye? DLK? hyperopic shift? diurnal vision fluctuation?
Dry eye + DLK = LASIK hyperopic shift + diurnal fluctuation = RK
Pincusin
Due to the fact that the edges of the lens have more mag, so the center looks further away and thus get the pincusion effect with high plus lenses.
Order of optic nerve meninges from outer to inner?
Dura mater --> arachnoid --> pia mater
As the water content of a soft hydrogel contact lens increases
Durability of the lens will decrease Permeability of the lens will increase Deposit formation will increase Patient will report an increase in dry eye symptoms
what is difluprednate
Durezol
Glass
High specific gravity and chips and shatters easily. But does block UV light, is scratch resistant and has a high abbe number meaning less chromatic aberration
The superior palpebral sulcus delineates which structures? A) The lacrimal portion of the lower eyelid and the ciliary portion of the lower eyelid B) The lower eyelid and the cheek C) The upper eyelid and the eyebrow D) The lacrimal portion of the upper eyelid and the ciliary portion of the upper eyelid E) The tarsal portion of the upper eyelid and the orbital portion of the upper eyelid
E) The tarsal portion of the upper eyelid and the orbital portion of the upper eyelid
As the interpupillary distance increases what happens to the amount of convergence (in prism diopters) needed to maintain fusion for a near target ? A. In decreases, but only for targets closer than 4 cm B. It decreases C. It increases, but only for targets closer than 4 cm D. It remains the same E. It increases
E. There is a direct correlation between the amount of convergence necessary to maintain fusion on a near target and interpupillary distance (IPD). As the IPD increases, so does the amount of convergence required to maintain fusion. Logically, this makes sense: if the eyes are further apart then they must rotate to a greater degree around the horizontal axis to maintain fusion if the target distance remains the same.
A 6-foot tall man wishes to buy a plane mirror in which he can visualize his whole length at the same time. How tall must the mirror measure in order for the above to occur? A.4.5 feet tall B.2.3 feet tall C.5.2 feet tall D.6 feet tall E.3 feet tall
E. 3 feet tall Explanation In order for a person to see their entire reflection, a plane mirror must be half as tall as the person. This holds true regardless of the position of the person. For the above example, 6/2= 3 feet.
Bests EOG + ERG will show
EOG = decreased light peak ERG normal
Euryblepharon
Elongated eyelid resulting in lateral poor globe apposition and causing a local area of exposure
Where is the highest concentration of crystallins in the lens?
Embryonic nucleus
Which type of dermal receptor primarily responds to temperatures below twenty degrees Celsius?
End-bulbs of Krause
Euryblepharon
Enlarged horizontal palpebral fissure --> partial lateral ectropion or poor lateral apposition of the eyelid to the globe
Corneal epi, stroma, endo reactions to hypoxia
Epi - erosions, edema, microcysts, ulceration, vascularization, decrease in cellular mitosis Stroma - edema, infiltrates, and vascularization Endo - blebs, folds, guttata and/or polymegathism
Goldenhar syndrome
Epibulbar/limbal dermoids Microphthalmos / anophthalmos blepharophimosis Upper lid notching Optic disc colobomas
What drains Schlemm's canal?
Episcleral veins
Where does whorl keratopathy deposit?
Epith
What layer of the cornea are deposits observed in cases of whorl keratopathy
Epithelium
Changes to lens with accommodation
Equatorial diameter decreases, front surface becomes more curved and moves forward, back surface remains stationary and does not change, the anterior chamber depth decreases and there is a momentary decrease in the IOP
Main bacteria --> traveler's diarrhea?
Escheria (E. coli)
Type of muscle movements in the GI system?
Esophagus and stomach - peristalsis Intestines - segmentation
Soft roids
Esters
What part of the ear serves in equalizing the air pressure between the middle ear and the atmosphere
Eustachian tube
APGAR score
Evaluating physical status right after delivery - haert rate, respiratory effort, muscle tone, reflex irritability, color Each graded on scale of 0-2. 8 or higher = good condition, 3 or less = poor condition
Evisceration, enucleation, and exteneration
Evisceration: removal of the iris, cornea, and internal contents of the eye; sclera and attached EOMS are intact. Enucleation: removal of the entire eyeball, leaving the eyelids and the adjacent structures intact. Exteneration: removal of the entire contents of the eye socket, including the eyeball and adjacent fat, muscles, and other nearby structures. In certain cases, the eyelids and the maxilla may also be removed.
Broken vessels on OCT
Excessive eye movement. Excessive blinking will result in dark bands
What type of bifocal has only one optical center?
Executive bifocal
Activities that decreases IOP
Exercise General anesthesia Alcohol consumption Marijuana use
You ask your patient to place a red lens in front of their right eye and proceed to perform the red lens test. Your patient reports seeing two images with the red image being perceived to the left of the white light. What type of deviation corresponds with the above findings? Hypophoria Hyperphoria Exophoria or exotropia Esophoria
Exophoria or exotropia As the red lens is placed over the right eye, your patient reports that his right eye sees a red light and the left eye sees a white light. In this case, the red light is perceived to the left of the white light demonstrating crossed diplopia. Crossed diplopia is characteristic of an exo deviation. The easiest way to remember this is that a cross makes an 'x', and 'exo' contains an 'x' so the 'x's always go together.
A 6-year old white male presents with a mild left head turn. Wet retinoscopy reveals OD: +0.25 OS: +0.50 with best corrected acuities of 20/20 in each eye. Extraocular movements show limited adduction of the left eye in right gaze. It is also noted that the left eye retracts with a narrowing of the eyelid fissure. What is the most appropriate diagnosis for this patient? A. Brown syndrome OS B. Duane Syndrome Type II OD C. Duane Syndrome Type I OS D. Duane Syndrome Type II OS E. Bilateral Brown Syndrome F. Duane Syndrome Type III OS
F. Duane Syndrome Type III OS In this case, Duane Syndrome is suspected due to the presence of an extraocular muscle deficit and the additional sign of eye retraction and narrowing of the eyelid fissure. Duane Syndrome Type III is the most appropriate diagnosis due to the limited ADDuction of the affected eye on right gaze, along with the left head turn, which also implies limited ABDuction as well. Duane Syndrome Type I describes limited ABDuction of the affected eye (the most common) as well as a possible compensatory head turn toward the involved side. Duane Syndrome Type II describes limited ADDuction of the affected eye, as well as a possible compensatory head turn toward the uninvolved side. Duane Syndrome Type III describes limited ABDuction AND limited ADDuction of the affected eye. It also usually presents with a compensatory head turn toward the involved side. A good way to remember the difference between the three types is that type I results in an aBDuction deficit (aBDuction has one D therefore it is type I). Type II causes an aDDuction deficit (aDDuction has two Ds therefore it is type II). Type III has three Ds, aBDuction and aDDuction-the number of the types matches the number of Ds in the deficit. Brown syndrome describes a limitation of elevation in adduction. It is a limitation of the superior oblique tendon.
Myerson's sign results from a failure to inhibit which reflex? Menace reflex Dazzle reflex Auditory reflex Corneal reflex Facial reflex
Facial reflex
First and second order aberrations
First - prism/tilting Second - refractive error
How does corneal edema affect IOP measurement?
False low
What factors can influence the efficacy of the Heijl-Krakau blind spot monitoring in perimetry? Size of stimulus Size of the optic nerve Iris color Fellow eye not patched appropriately
Fellow eye not patched appropriately
Normal maximum ESR
Female: add 10 to age and divide by 2 Male: divide age by 2
Any optical system in air has first and second nodal points that coincide with which of the following corresponding points? The geometrical center of the optical system First and second focal points Front and back surfaces of the optical system First and second principal points
First and second principal points The first and second nodal points (N and N') of an optical system are unique conjugate points such that an incident ray directed at N yields a final ray emerging from N' that is undeviated and parallel to the initial ray. For any optical system in air, the first and second nodal points (N and N') correspond to the first and second principal points (P and P').
Blood agar
For things that lyse blood cells
Maxillary nerve
Foramen rotundum. Both mean big
Three primary portions of embryonic neural tube development
Forebrain (prosencephalon) Midbrain (mesencephalon) Hindbrain (rhombencephalon)
Tertiary vitreous
Forms last and is where lens zonules are embryonically derived from
MRSA drugs?
Fortified vancomycin is best Bacitracin Polytrim® Fourth and fifth generation fluoroquinolones
Haversian canals
Found in compact bone tissue; house blood vessels and nerves
Spherical aberration, tetrafoil and oblique astigmatism are known as
Fourth-order aberrations that cannot be corrected for by spherocylindrical lenses
Which facial muscles are responsible for retraction of the eyelids
Frontalis Levator palpebrae superioris Muller's
Eyelid opening
Frontralis, also innervated by CN VII
Area of Martegiani
Funnel-shaped dilation surrounding optic disc Represents posterior termination of Cloquet's canal
What type of bacteria produces spores?
G+ rods only
Type of bact: Gonorrhea
G- cocci
Type of bact: Pseudomonas
G- rod
3 other culprits besides emboli to consider for a CRAO
GCA Sickle cell IV drug use (all cause arterial clots)
Which of the following topical antimicrobials, if administered for equal amounts of time, displays the greatest amount of corneal toxicity? Erythromycin Ofloxacin Tobramycin Polytrim® Gentamicin
Gentamicin can cause punctate epithelial erosions, delayed re-epi, and corneal ulceration
What gland is affected in external hordeolum?
Gland of Zeiss
Three reflexive afferent pathways that involves the optic nerve
Glare reflex Dazzle reflex Menace reflex
Glutathione
Glutamine, cysteine and glycin
Thayer martin
Gonorrhea
According to the Standardization of Uveitis Nomenclature (SUN) guidelines, the presence of about 20 visible cells in a 1mm by 1mm high-powered field is consistent with which of the following grades? Grade 1+ cells Grade 2+ cells Grade 0.5+ cells Grade 4+ cells Grade 3+ cells
Grade 2+ cells
Pmonas in a micro lab =
Gram neg. rod oxidase (+) grape odor blue green pigment
Cetrimide agar
Gram negative
Avellino dystrophy
Granular dystrophy type 2. Deposition of amyloid and hyaline in stroma.
Pertibial myxedema is an infiltrative dermopathy that is most commonly associated with
Graves disease
cimetidine & ranitidine =
H2 antagonists
Human leukocyte antigen (HLA) types
HLA-B51: Bechet's syndrome HLA-B27: Spondyloarthropathies (ankylosing spondylitis) HLA-A29: Birdshot chorioretinopathy HLA-B7 & HLA-DR2: Presumed ocular histoplasmosis syndrome (POHS) and acute multifocal placoid pigment epitheliopathy (AMPEE)
keratometry - mires look elliptical, with long axis located vertically. which meridian is steeper?
HM is steeper (x180) steeper H meridian minimizes the horizontal image, making V appear longer ATR cyl (90 +/- 30*)
Phacolytic glaucoma
HMW proteins that have leaked into the AC through an intact lens capsule from a hypermature cataractous crystalline lens --> obstruct TM --> significant elevation in IOP
name the DNA enveloped viruses
HSV VZV CMV EBV Hepatitis B smallpox
How to assess SCL centration
Have the patient look in primary gaze without blinking; measure the amount of decentration (if present) of the soft contact lens; this may be in any direction
How to assess SCL lag
Have the patient move from primary gaze to lateral gaze; measure the amount the soft contact lens moves relative to the cornea
How to assess SCL sag
Have the patient move from primary gaze to superior gaze; measure the amount the soft contact lens drops
Acrosome
Head of sperm that allows penetration into female gamete
4 types of pts who classically develop neurotrophic keratopathy
Herpes DM stroke CL overwear
What types of acute anterior uveitis typically results in *elevated* IOP
Herpes Posner-Schlossman syndrome
Direct ophthalmoscopy mag
Higher mag and less field of view for myopes.
Reed sternberg cells
Hodgkin's
How to adjust nylon frames?
Hot water
How do photoreceptors signal the presence of light? Depolarization Release epinephrine at postsynaptic junctions Repolarization Hyperpolarization Release dopamine at postsynaptic junctions
Hyperpolarization
Acute periorbital edema
Hypothyroidism or nephritis
Prism and seg height
If BD prism is in the Rx, this will shift the image up and thus the bifocal should be shifted up with the image
How to tighten a loosely-fitting gas-permeable lens?
If a gas-permeable lens is fit too loosely, the most commonly-altered parameter of the lens is a steepening of the base curve. One can also choose to increase the optic zone, increase the overall diameter (OAD), narrow the peripheral curve system, or steepen the peripheral curve system.
Rh- moms
If the baby is Rh+, the mother's antibodies will lyse the baby's RBC's.
Which AB crosses blood-placenta barrier
IgA
Ciliocapsular fibers
Important for supporting the lens and accommodation. Arises from the sides and valleys of the ciliary processes and inserts onto the lens.
Megakaryocytes
In bone marrow; are responsible for producing thrombocytes (required for blood clotting)
in order to try to provide adequate rotational stability, front surface toric gas-permeable contact lenses must have at least 1-2 diopters of base-down prism added to the lens to aid in stabilization during blinks and eye movements
In conjunction with the addition of base down prism, the center thickness of the contact lens should be increased by 1.0mm for each prism diopter.
How does brow adipose tissue play in temperature regulation?
In extremely cold temperatures when shivering doesn't work anymore --> non-shivering heat production to increase metabolic rate (metabolizing the brown adipose)
According to the Food and Drug Administration (FDA), all DRESS lenses must be able to pass the drop-ball test in order to test impact resistance. What are the requirements of this test?
In order for a dress lens to be deemed impact-resistant (not shatter-proof) by the FDA, it must be capable of withstanding a 5/8 inch steel ball weighing 0.56oz dropped from a distance of 50 inches. The lens must not fracture. If the lens is laminated and its lamina cracks but the lens does not, the lens is considered safe.
Pilomotor response
In response to cold; body hair stands erect --> creates air pockets to retain heat
Where is hippocampus located, what it's responsible for
In temporal lobe Spatial orientation, memory (esp association of smell to past memories)
You are providing follow-up care for a patient prescribed a low Dk soft contact lens worn on an extended wear basis. When would you most likely observe striae?
In the early morning after the first night of overnight wearing
What is subdural space?
In the event of injury - dura separates from arachnoid
Segmentation
In the intestines. Peristalsis is in the stomach and esophagus
How to adjust fitting height of PAL for child?
Increase by 4mm
The change in the distance refractive error that commonly occurs during pregnancy is due to
Increase in central corneal thickness; thereby influencing the refractive index of the cornea occurs as a result of edema and fluid retention caused by changes in circulating hormone levels. Patients will typically present with a complaint of blurred distance vision, and a manifest refraction will reveal a myopic shift. The increase in myopia may be attributed to the fact that swelling of the cornea will increase the cornea's refractive index and reduce the radius of curvature (steepen the corneal curvature). These changes are typically transient, and refraction usually returns to baseline within a few weeks after giving birth.
Ocular changes seen in pregnancy?
Increase in corneal thickness Decrease in corneal sensitivity Decrease in IOP (increased outflow) Reduced tear production Ptosis, ocular motility defects Krukenberg spindle (but no other signs of pigment dispersion)
Pterygium
Increased with the rule
How does blinking affect IOP?
Increases it
How does the addition of a competitive inhibitor change the Lineweaver-Burk plot of an enzyme? Increases the y-intercept Decreases the y-intercept Decreases the slope Increases the slope
Increases the slope
Defns of "infectivity, invasiveness, pathogenicity, virulence"
Infectivity - ability to initiate a site of infection Invasiveness - ability to spread to different sites of the body Pathogenicity - ability to cause sickness/disease Virulence - degree of pathogenicity
What area of the retina is MOST commonly affected by WWP?
Inferior temporal
blue-gray stromal opacities =
Salzmann's nodular degen
What location of the optic nerve head is most likely to exhibit a drance hemorrhage
Infero-temporal quadrant
Pretibial myxedema
Infiltrative dermopathy most commonly associated with Grave's disease (but also be found in Hashimoto's). Typically presents as waxy, discolored, raised plaques of non-pitting edema of the skin
Cyclosporine is commonly used topically to treat certain eye conditions including keratoconjunctivitis sicca (KCS). Which of the following is a known mechanism of action for cyclosporine? Stabilization of mast cells Inhibition of T-cell activation Inhibition of cyclooxygenase (COX) Antagonism of vitamin K
Inhibition of T-cell activation While the exact mechanism of action of cyclosporine remains controversial, it is generally accepted that cyclosporine inhibits calcineurin in CD4+ T helper cells which, under normal circumstances, are responsible for production of interleukin-2 (IL-2). IL-2 normally stimulates activation and proliferation of cytotoxic T cells and other helper T cells. Cyclosporine prevents this activation and acts as an anti-inflammatory. One of the major causes of KCS is autoimmune destruction of lacrimal cells by T cells. Therefore, topical cyclosporine can be protective. In all likelihood, there are likely additional mechanisms of action for cyclosporine in the treatment of KCS, but this is one of the most accepted mechanisms and is the best option from the choices given here.
Vital capacity of the lungs is calculated by the summation of
Inspiratory reserve volume Expiratory reserve volume Tidal volume
Job of Helper T cells
Interact with Ag-presenting cells Stimulate proliferation of specific B and T lymphocytes
Intraocular inflammation that predominantly involves the vitreous is known as
Intermediate uveitis
What are T cells' primary targets
Intracellular pathogens Organ transplants Tumor cells
As we age, what is expected to happen to intraocular pressure? Intraocular pressure decreases Intraocular pressure increases Intraocular pressure remains the same
Intraocular pressure increases
What are causes of a non-responsive iritis (anterior uveitis) with topical steroids
Intraocular tumor Leukemia Metastatic cancer Non-Hodgkin's lymphoma
What is the primary route of infection of patients diagnosed with hepatitis C?
Intravenous drug use
Pinhole camera
Inverts the image and is in focus no matter where the screen or object is. The image brightness stays constant as the object distance is changed and the image distance is unchanged
Most common cause of ectropion?
Involutional ectropion; caused by stretching and laxity of the medial and lateral canthal ligaments and by retractor dehiscence. Associated with aging and is most often seen in individuals over the age of 60.
Conditions that cause a pseudoptosis appearance?
Ipsilateral hypotropia Dermatochalasis Contralateral lid retraction Brow ptosis Lack of support of the lids (due to an orbital volume deficit)
Berlin nodules
Iris nodules indicative of chronic granulomatous uveitis; found in the angle (viewed via gonio)
Ferry's line
Iron pigmentation at edge of filtering bleb
What are ADEK vitamins, cholesterol, steroids, coenzyme Q made of?
Isoprenes or terpenes
Your advanced glaucoma patient brings in a broken telescope that he would like to replace. Looking at the telescope, how can you tell that it is a Keplerian design? By the length of the telescope It has a virtual exit pupil By the weight of the telescope It has a real exit pupil By the amount of magnification of the telescope
It has a real exit pupil
What is subpial space?
It shouldn't exist in a healthy person - pia is very tightly adhered to brain, spine, nerve
prominent corneal nerves, guttata, & posterior shagreen are all common observations in
KCN
onset of KCN vs pelludcid
KCN = visual changes around puberty pellucid = progressive visual loss in 20s and 30s
Which systemic neuromuscular conditions affects EOMs
Kearns-Sayre syndrome Grave's ophthalmopathy MG Myotonic dystrophy
How to adjust lens when you see mucin balls
Keep the patient in the same lens but re-fit into a steeper base curve. Alternatively, one can decrease the amount of extended wear or add re-wetting drops to the patient's contact lens regimen. Upon removal, mucin balls will cause pooling of sodium fluorescein but will not cause staining of the cornea.
What is Kenalog
Kenalog is a steroid that may be injected into resistant chalazia to expedite resolution. Adverse side effects include pain on injection, temporary skin atrophy, subcutaneous white deposits, depigmentation of the eyelid at the injection site, retinal and choroidal vascular occlusion, and increased IOP.
Diabetes and smoking are protective against what disease?
Kerataconus
Diabetes and smoking have been demonstrated to potentially serve as protective factors against
Keratoconus Glaucoma
What does blue target/yellow background test?
Konio pathway
What is considered pathognomonic for rubeola (red measles)
Koplik's spots
Pathognomonic for rubeola?
Koplik's spots - white-blue spots w/ red halos on buccal mucous membranes
Natural amino acids in proteins
L
Corneal ulcer
Lid edema and AC reaction, photophobia, circumlimbal injection, tissue thinning
Additive color mixture
Light from two different origins are added together --> combined effect possesses a greater amount of light than either of the two sources alone
42-year old construction worker. OHx: History of getting plaster in his right eye. CC: Pain, foreign body sensation, and photophobia. His acuity is reduced in that eye to 20/50 with a normal pupillary response. What type of chemical trauma did the worker experience, and what would be your first therapeutic intervention?
Lime, particularly in the form of plaster, is the most commonly encountered alkali injury. Fortunately, it tends to cause a less severe burn than other types of alkali burns. The rapidity with which pH abnormalities of the ocular surface are neutralized has a significant impact on the subsequent clinical course. Irrigation for a minimum of 30 minutes and checking pH of tears for evidence of neutrality is recommended. *Bases are worse than acids in the eye. Acids denature proteins and are eventually limited in spread but bases keep going.
Ependymal cells
Line cavities of CNS and the ventricles in the brain and make up the epithelium of the choroid plexus which makes CSF
Ependymal cells
Line cavities of the central nervous system + walls of the ventricles of the brain. Collectively, these cells form the epithelium of the choroid plexus, which secretes cerebrospinal fluid.
In order to maximize drug penetration through the cornea an ophthalmic drug or its vehicle should possess which property? Highly polar component High alcohol content High pH Lipid solubility
Lipid solubility Ophthalmic drops that are comprised of both lipid (non-polar) and water-soluble (polar) components result in the most effective preparation. The tight junctions of the corneal epithelium keep hydrophilic drugs out but allow good penetration for lipid-soluble drugs. In contrast, the corneal stroma demonstrates good penetration for water-soluble agents. However, a HIGHLY polar agent will not cross the corneal epithelium; therefore, a mildly polar substance is advantageous over a highly polar agent. One should NEVER place alcohol on the eye as it will instantly debride the corneal epithelium; ALWAYS rinse all instruments used for ocular procedures with saline solution after sterilization with any agent that could be toxic to the cornea. Solutions with high pH (basic) are more damaging to the cornea than solutions with a lower pH (acidic). It is important to use solutions that are close to a neutral pH (7.0) to eliminate possible damage to the cornea.
Smooth ER
Lipid synthesis and storage of calcium
In order to determine if environmental elements aid in the development of ametropia, researchers reared an infant monkey with a clear lens placed over one eye. These studies determined that putting a minus lens over one eye induced which type of refractive error? Presbyopia Hyperopia Large amounts of astigmatism Myopia
MYOPIA Although there has been much debate in the past over whether or not the etiology of refractive errors was environmental versus inherited, it is now believed that both factors contribute to the development of ametropias. Hung et al, 1995 demonstrated that by placing a prescription lens over one eye of an infant monkey and removing it after the eye had reached maturity, the mature eye developed the refractive error that the lens is normally meant to neutralize. A minus lens induced myopia and a plus lens induced hyperopia. Regardless of whether the etiology of the refractive error is inherited or environmental, it is absolutely essential that a clear retinal image be present in order for emmetropization to occur.
What types of cells make up "mutton-fat" keratic precipitates (KP)
Macrophages Epithelioid cells
Macula occludens v. adherens junctions?
Macula occludens - tight junctions that tend to be between cells of the same layer Adherens junctions - tight junctions that tend to anchor cells to other layers (more basal)
Long-term complications of bleph
Madarosis Trichiasis Neo of lid margin Keratitis Erythema Phlyctenule formation Infiltrates
IgM
Made first (in primary or first exposure) and is the heaviest antibody because it can be a pentamer
What does flickering target on perimetry test?
Magno pathway
Megakeratocytes
Make thrombocytes and are in bone marrow
Peripheral curve
Making them shorter makes them tighter and lengthening them makes them looser
How to manage interferon retinopathy
Management of the ophthalmologic side effects associated with interferon treatment is typically tailored to the patient's symptoms. If a patient presents with retinal findings but is asymptomatic, the prescribing physician will usually recommend continuing interferon therapy at the same dose with close observation. However, if retinal complications cause the patient to become symptomatic, either withdrawing treatment altogether or decreasing the dosage of the interferon therapy should be considered.
Systemic diseases --> lens sublux
Marfan's Ehler Danlos Homocystinuria Weill-Marchesani
4 conditions that can cause sublux
Marfans (displaces ST) Ehlers-danlos Weill-Machesani (inferior, bilateral) Homocystinuria (inf)
mnemonic for stromal dystrophy deposits
Marilyn Monroe Got Hers in LA macular- mucopolysacchs granular- hyaline lattice- amyloid (fleck = GAGS)
Omega 3 fatty acids
May raise LDL but also raises HDL, decreases triglycerides and lowers BP
What controls normal breathing?
Medulla oblongata
Which of the conditions listed below is considered X-linked? Meesman's dystrophy Reis-Buckler Dystrophy Anterior Basement Membrane Dystrophy Megalocornea Macular Dystrophy
Megalcornea all the corneal dystrophies are AD except macular is AR
Skin surface receptors
Meissner's = low frequency vibrations End bulb of krause = temp less than 20 celcius Ruffini = constant touch and temp over 45 celcius Pacinian = deep and rapid pressure changes related to vibrations and touch
Vaccines protect the body from subsequent infection due to the presence of
Memory T cells
Patients with which type of refractive error are most likely to experience a decrease in IOP following cataract surgery
Moderate hyperopia
Glands of moll
Modified apocrine at base of lashes
Golgi
Modifies new proteins and packages and sorts macromolecules for secretion from the cell or use within the cell
Cell responsible for walling off bact and creating granulomas?
Monocytes
Patient with a high AC/A ratio, how would you expect the phoria to change as the target is brought closer to the patient
More eso or less exo
Where is the prism reference point on progressives?
Same location as MRP - below the fitting cross
Methods of treating depression?
Most drugs: increase seratonin/NE levels (block reuptake or downregulate B receptors) MAO inhibitors --> increase seratonin/NE levels Increase Ach levels Increase dopamine levels
Nonesense mutations
Most likely from a point mutation, substitution of a single base that leads to a stop codon
Astrocytes
Most numerous and offer support and structure to the brain. Also play a role in making the BBB as well as removal of neurotransmitters from synaptic cleft and removal of excessive extracellular
What are mucin balls?
Mucin balls appear as small, white, pearl-like debris that occur behind the posterior surface of contact lenses. They generally occur with silicone hydrogel lenses that are too flat and are used for extended wear purposes. Mucin balls typically are not a threat to vision. Mucin balls may cause dimpling of the corneal surface which may be mistaken for microcysts. A simple way to distinguish between the two is that microcysts are smaller and they will appear darker with indirect illumination.
Vit A
Mucous, goblet cells and bitot spots. Retinoid, active form is retinol and necessary for the formation of retinol
Which cells are the last to develop within the neural retina? Ganglion Horizontal Amacrine Rods Mueller
Mueller
Bichrome VA chart uncorrected. OS occluded, letters on the red side of the chart appear blacker and darker. OD occluded, letters on the green side appear blacker and darker. What would likely be the refractive condition OD OS?
Myopia and hyperopia -- For an emmetropic eye that is not accommodating, the chromatic interval within the eye would be positioned so that the anterior (green) and posterior (red) ends of the interval are equidistance from the retina.
2nd order aberrations
Myopia, hyperopia and astigmatism. Defocus
General characteristics of those likely to have larger pupils?
Myopic Young Lighter irises
silver nitrate treats
N gonorrhoae esp neonatorum
Hutchinson's sign associated with herpes zoster is an indication of reactivation of which of the following cranial nerves? Lacrimal branch of the trigeminal nerve Nasociliary branch of the trigeminal nerve Frontal branch of the trigeminal nerve Facial nerve
Nasociliary branch of the trigeminal nerve A vesicular eruption on the tip of the nose in patients with herpes zoster indicates the reactivation of herpes involving the nasocilary branch of the ophthalmic division of the trigeminal nerve. This sign may provide an early predictive factor of impending eye involvement (herpes zoster ophthalmicus).
A and V patterns
Need to be more than 10-15 prism diopters
Proteoglycans
Negatively charged and keep proper spacing of collagen in the corneal stroma
neurogenic ptosis
Neurogenic ptosis is caused by an innervational defect to the levator muscle, most commonly as a result of a third cranial nerve palsy or Horner's syndrome (oculosympathetic palsy). A third cranial nerve palsy often presents with a complete ptosis, while a Horner's syndrome will display both a subtle upper and lower eyelid ptosis. Other less common syndromes associated with neurogenic ptosis are Marcus Gunn jaw-winking syndrome, in which a ptotic eyelid elevates with jaw movement, and third nerve misdirection wherein bizarre upper eyelid and eye movements occur usually after an acquired third nerve palsy.
What types of cells make up stellate KPs
Neutrophils Lymphocytes
Myasthenia gravis is an autoimmune disease that affects which of the following types of receptors in the body
Nicotinic acetylcholine receptors
Myasthenia gravis is an autoimmune disease that affects which of the following types of receptors in the body? Alpha-adrenergic Beta-adrenergic receptors Muscarinic acetylcholine receptors Adenosine receptors Nicotinic acetylcholine receptors
Nicotinic acetylcholine receptors
Which medication class is contraindicated in patients on Viagra due to potentially fatal drop in blood pressure
Nitrates
Viruses with this characteristic are significantly more resistant to environmental degradation; in other words, they survive longer in the environment.
Non-enveloped viruses
Pericytes
Not in the choroid but they are in the choriocapillaris, only in retinal arteries for autoregulation
What is the proper sequence of enzymes used to correct damage done to DNA by ultraviolet (UV) light? DNA ligase, DNA polymerase I, Nuclease Nuclease, DNA ligase, DNA polymerase I DNA polymerase I, DNA ligase, Nuclease DNA polymerase I, Nuclease, DNA ligase DNA ligase, Nuclease, DNA polymerase I Nuclease, DNA polymerase I, DNA ligase
Nuclease, DNA polymerase I, DNA ligase
What part of G- bact do we form antibodies to?
O side chain (aka O antigen)
what part of bacterial cell wall causes immune rxn + is responsible for the creation of ABs by the host?
O side chains "O antigen" -specific to certain bacteria -some bacteria can change their O side chains to avoid detection
entrance pupil of a telescope =
OBJECTIVE lens diameter
Optical density equation
OD = log(1/Transmission fraction)
pt has unilateral mid-peripheral hemes, gradial vision loss + occasional periorbital pain. Dx?
OIS hemes may be only sign! dot/blots 360 on BIO need carotid doppler
Retinal colobomas result from an incomplete closure of
Optic fissure
What conditions mimic glaucomatous visual fields?
Optic nerve drusen Ischemic optic neuropathy BRAO, other vascular occlusive disease
what cell types are found in papillae
PMNs + eosinophils (PMNs destroy bacteria, eosinos assist with allergic rxns)
Histo triad =
PPA punched-out periph Maculopathy (incl. CNVM) CHOROIDITIS!!!
Epidemic v. pandemic?
Pandemic - epidemic breakout of a disease across a large geographical area (i.e. several countries) Epidemic - rapid outbreak of a disease that affects many individuals at the same time and is well above a predicted rate for a given area or community
Tilt
Pantoscopic and faceform will both increase the sphere power and induce cylinder that is at the axis of rotation and will be the same power as the sphere power. So a minus lens that is pantoscopically tiled, the sphere will become more minus and more minus cyl will be induced at the 180
Which of the following is most common early pattern of a glaucomatous visual field defect
Paracentral scotoma
Mercaptopurine
Part of a class of drugs referred to as purine antagonists, commonly used to treat acute lymphocytic leukemia, Crohn's disease, and ulcerative colitis
Paratrope
Part of antibody that interacts with antigen. Epitope is part of antigen that interacts with antibody
Which patients are most likely to possess large pupils
Patients who are near-sighted, young or possess lighter-colored irides
Visual field for foster-kennedy syndrome
Patients with Foster-Kennedy syndrome will commonly present with a central scotoma corresponding to the eye with the atrophic optic nerve (ipsilateral to the side of the lesion) and a normal visual field in the contralateral eye. This also typically holds true for any other etiology that leads to optic disc edema and optic atrophy. Usually, eyes with optic disc edema do not show a visual field defect, and visual acuity is typically normal (unless chronic); this is in contrast to eyes with optic atrophy, in which visual field testing commonly reveals a central scotoma and visual acuity is usually severely reduced.
Types of JIA
Pauciarticular (50%) - <4 joints affected (large joints), uveitis in 20% Polyarticular (20%) - 5+ joints affected (smaller), uveitis in 5% Systemic - sx of fever, pink rash in addition to arthritis; small and large
Which of the following ocular diagnostic pharmaceutical agents is MOST commonly used to aid in the diagnosis of an Adie's tonic pupil? Hydroxyamphetamine Cocaine Pilocarpine Tropicamide Phenylephrine
Pilocarpine
Dissection of the eye reveals that the ciliary body is actually triangular in shape. The apex of this triangle points in which direction and is continuous with which structure? Points anteriorly; continuous with iris Points posteriorly ; continuous with scleral spur Points posteriorly; continuous with choroid Points anteriorly: continuous with ora serrata
Points posteriorly; continuous with choroid
UV blocking by poly? CR-39?
Poly - blocks all of UVA and B CR-39 - 100% of B, some of A
Polymegathism v. pleomorphism
Polymegathism - change in cell size Pleomorphism - change in cell shape
Which of the following conditions occurs as a result from changes to Descemet's membrane? Reis-Buckler's dystrophy Lattice dystrophy type I Fleck dystrophy Posterior polymorphous dystrophy
Posterior polymorphous dystrophy
Which of the following conditions occurs as a result from changes to Descemet's membrane?
Posterior polymorphous dystrophy Appears as gray/white vesicles or rings within Descemet's membrane, often described as a "railroad track"
What pupil fibers are damaged in Adie's? (pre/post ganglion, para or symp)
Postganglionic parasymp
A 52 year-old female presents in your office with a concern that her right pupil appears significantly larger than her left. Upon instillation of 10% cocaine, her right pupil dilates but her left pupil does not. You bring her back the next day and instill 1% hydroxyamphetamine in both eyes, and both pupils dilate. What is the BEST diagnosis for this patient? Post-ganglionic parasympathetic nerve palsy Post-ganglionic sympathetic nerve palsy Pre-ganglionic parasympathetic nerve palsy Pre-ganglionic sympathetic nerve palsy
Pre-ganglionic sympathetic nerve palsy In pre-G, both pupils dilate In post-G, abnormal pupil does not dilate
HTN headache
Present upon awakening, go away at some point. Coffee helps.
Timeline of primary and secondary vitreous formation?
Primary - 3 weeks Secondary - 9 weeks
IgG
Primary antibody in the blood, smallest and can cross placenta.
A mother brings in her 12 month-old son, reporting that he frequently rubs his eyes and that they constantly appear to be tearing. Further investigation with a 20 D lens and a transilluminator reveals enlarged, cloudy corneas and horizontal striae. Fundus exam reveals an excavated optic nerve. Given the exam findings, what is the MOST likely condition observed in the young infant? Dacryocystitis Primary congenital glaucoma Leber's hereditary optic neuropathy Incomplete dehiscence of the valve of Hasner
Primary congenital glaucoma
Prism and retinal image
Prism shifts the retinal image towards the base
What is the term used for addition of prism in PALs
Prism thinning
What should not be done during an acute infection of dacryocystitis
Probing, dilation and/or irrigation of the lacrimal system
DNA annealing
Process of formation the double helix
Where are sperm produced? Maturation and storage site?
Produced in seminiferous tubules of testicles Epididymis - maturation and storage
What does the pentose phosphate shunt produce? What does this end product do?
Produces NAD*P*H Used for fatty acid steroid synth
Values of prolate v. oblate eccentricity?
Prolate - 0.1 to 0.9 (avg of 0.5-0.6) Oblate - negative 0.1 to neg 0.9 (seen in post-LASIK corneas)
Mitosis
Prophase (condensing,) metaphase (central lining,) anaphase (pulling apart,) telophase (cytoplasm division and formation of new nuclear envelopes.)
Genetic recombination, which allows for genotypic and phenotypic variations, occurs during which phase of meiosis? Metaphase II Telophase II Anaphase I Prophase I
Prophase I
GLC contraindicated in iritis
Prostaglandins and miotics/cholinergics
Accessory glands to sperm
Prostate Seminal vesicles Bulbourethral gland
Long-term wear of a superior positioning "lid attachment" gas-permeable (GP) fitting relationship will typically result in what corneal topography pattern?
Pseudo-KCN - flattened superiorly, steepened inferiorly Lid attached CLs - fit flat or on-K
Blindsight
Pt have some visual function but are unaware of it and deny its existence. They lack awareness of visual stimuli, but respond to it.
Pupillary membrane remnant v. hyaloid membrane remnant?
Pupillary membrane - in front of the lens Hyaloid membrane - behind the lens
Mucopurulent vs purulent
Purulent for gonococcal infections Mucopurulent for acute bacterial infections
What is the Turnville binocular refraction method, and when can't it be used?
Putting a septum in front of the pt --> no central fusion Not good in those who suppress an eye - strab, high phorias, ambly
Which of the following is NOT a ketone body? -Acetone -Acetoacetic acid -Pyruvate -Beta-hydroxybutyric acid
Pyruvate
Which AI has an established association with scleritis?
RA --not Behcet's or Ankylosing spondyloarthritis (these are assoc w/ uveitis or iritis)
gold salts are rxed for
RA => depo of gold in skin, lens + cornea = gray discoloration of skin + brown/gold deposits in DEEP STROMA
Tissue cells that are insulin-independent
RBC Brain cells Lens fibers cells Kidney cells
Schafer's sign =? indicates
RBC or pigment in vitreous retinal break (but you can still have a retinal break with (-)Schafers)
list 5 conditions for which bandage CLs are often used
RCE Entropion / Trichiasis Filamentary keratitis Thygesons SPK Bullous keratopathy
What structures does the neural ectoderm give rise to?
RPE, neural retinal fibers of ON, neuroglia, CB epithelium, iris epithelium (inc sphincter + dilator)
the 2 levodepression muscles =
RSO + LIR (both depress eye into left gaze)
Depth of field
Range of distances in object space for which objects point appear to be in focus for a fixed position of the image plane (without accommodation)
Melanocytoma
Rare tumor at optic nerve with feathery borders, is in the NFL and may appear elevated
Which type of involuntary accommodation is stimulated by blurring of the retinal image? Proximal Reflexive Tonic Convergence
Reflexive
Laser thermal keratoplasty
Refractive surg for hyperopes/presbyopes Uses holmium laser to shrink peripheral corneal collagen Reverts in 2-3 yrs
T/F: EKC causes PAN and sometimes pseudomembranes
true
Which of the following conditions is MOST frequently seen in association with normal tension glaucoma? Raynaud's phenomenon Hypoglycemia Peripheral neuropathy Homocystinuria
Raynaud's phenomenon
Which of the following conditions is MOST frequently seen in association with normal tension glaucoma?
Raynaud's phenomenon (peripheral vasospasm) Peripapillary atrophy Drance hemorrhages Paracentral scotomas
End-bulb of Krause
Reacts to temperatures less than twenty degrees Celsius
Kestenbaum's rule to find starting ADD power read standard newspaper print
Reciprocal of patient's distance VA
What of the following methods of drug administration is subject to first pass metabolism
Rectal Oral
What cells do not have insulin receptors? How do they get their glucose?
Red blood cells, brain cells, lens fiber cells, and kidney cells Get it via diffusion / concentration gradient
Which of the following acquired color vision deficiencies would you MOST expect to see in optic nerve disease and macular disease, respectively? Red-green, blue-yellow Blue-yellow, rod monochromacy Red-green, rod monochromacy Blue-yellow, red-green
Red-green, blue-yellow
Lens modifications that can loosen a tight-fitting RGP lens
Reduce overall diameter Reduce the optic zone width Flatten the base curve Flatten the peripheral curves Widen the peripheral curves Increase the blend between the peripheral curve
hodgkins pts have what 2 types of cells
Reed-Sternberg cells = diagnostic Hodgkins cells are NOT fully diagnostic but are highly suggestive. (hodgkins = large mononuclear cells w/ retinculated chromatin; either 1 or 2 prominent nucleoli. RS cells = same but multinucleated)
You correctly diagnose a 3-month old baby with unilateral anterior persistent hyperplastic primary vitreous (PHPV). What is the MOST appropriate treatment? Monitor carefully every three months Prescribe sunglasses to ensure UV protection Prescribe patching therapy of the good eye Refer to ophthalmology for a lensectomy
Refer to ophthalmology for a lensectomy
T/F: FQs don't cause SPK like aminoglycosides
true
Job of the thalamus
Relay of sensory information - projects the sensory signals to the correct destination
Prostaglandin with BID dosing?
Rescula
Spirometry
Residual volume = Whats left after max expiration Expiratory reserve volume = Amount that can be exhaled after a tidal exhalation Functional residual = Amount of air in lung after tidal exhalation Vital capacity = Max air that can be exhaled after max inhalation
Ruffini endings
Respond to constant pressure and touch as well as temperatures above 45 degrees Celsius
What ocular structure has the greatest oxygen consumption rate
Retina
Neural ectoderm
Retina and its continuations including CB epi and iris epi
Which of the following structures has the greatest oxygen consumption rate? Lens Cornea Brain Retina
Retina! 2x higher than brain 2-5x more than cornea 10x more than lens
difference btwn RP, choroideremia, gyrate atrophy, and Vit A deficiency?
Retinitis pigmentosa is characterized by progressive loss of photoreceptor and retinal pigmented epithelial function (RPE), affecting both the rods and cones (rods > cones) • Choroideremia is characterized by diffuse progressive degeneration of the choriocapillaris and overlying RPE • Vitamin A deficiency can cause ocular dryness and eventual complete blindness secondary to vitamin A's role in signal phototransduction • Gyrate atrophy is characterized by bilateral chorioretinal degeneration resulting in a scalloped appearance of the peripheral retina
Aspirin has been linked with what syndrome in children?
Reye's syndrome
Chryiasis (*gold deposits*) of the cornea occurs secondary to the administration of medication used to treat with systemic condition
Rheumatoid arthritis
Chrysiasis of the cornea occurs secondary to administration of medication used to treat which of the following conditions? Rheumatoid arthritis Hypertension Cancer Cardiac arrhythmias Diabetes
Rheumatoid arthritis
Onchocerca volvulus
River blindness
Types of rotary astigmatic dials and how they work
Rotary-T dial Arrowhead dial Raubitschek (paraboline) dial Rotate the target, when pt says it's darkest start adding power to the cyl
Best edge profile for comfort in RgP?
Round edge Plus edge
Koplik's spots are pathognomonic for
Rubeola (red measles) -paramyxovirus spots are on buccal mucus membs: white-blue spots surrounded by red halos -kids 5-15 -fever, bloodshot eyes, sore throat, coughing, maculopapular rash on trunk,limbs,face, neck -cjvitis, photophobia Self-limiting; palliative Tx (ATs)
First cells to be damaged in glaucoma?
S cones Magno cells (use frequency doubling perimetry)
What bact causes impetigo?
S. pyogenes S. aureus
Heart conduction
SA node, AV node, bundles of HIS in the septum to purkinje fibers. Small delay at AV node to allow for completion of atrial contraction and ventricular filling
FDA says be out of SCLs how long before any customized procedure like LASIK? RGPs?
SCLs - 2 weeks RGPs - minimum 1 month, recommend 1 month for every decade of wear or until topo is stable.
Blepharochalasis
Seen in younger to middle-aged adults Excess swelling/deswelling of tissue (edema, inflamm) --> baggy eyelids --> eventual ptosis
Your patient has a tumor within the muscle cone behind the eye. Which of the following would you NOT expect? Sensory loss to the cornea Lateral rectus palsy Sensory loss to the upper eyelid Sensory loss to the tip of the nose
Sensory loss to the upper eyelid -that's FRONTAL nerve (NFL) only the NOA nerves go thru the CTR.
Central sulcus
Separates the primary motor cortex and primary somatosensory cortex & the frontal lobe from the parietal lobe
Which of the following retinal conditions is the MOST common complication associated with the presence of an optic disc pit? Optic disc edema Primary open angle glaucoma Serous macular detachment Choroidal neovascular membrane Central serous retinopathy Optic disc coloboma
Serous macular detachment
What ocular condition is MOST likely to develop secondarily to optic nerve pits?
Serous macular detachment (up to 45% with poor prognosis)
Contrast sensitivity function in elderly
Shifted to the left due to loss of high spacial frequency
Job of VLDL
Shuttle lipids from liver to other tissues
CAI's
Similar to sulfas, so if they are allergic to one, they are allergic to the other
Herpes keratitis
Simplex will stain centrally with fluorescein, will have terminal end bulbs, lesions will be larger and will respond to antivirals. Zoster stains with rose bengal, does not have terminal end bulbs, dendritic lesions are smaller and may not respond to antiviral therapy
Medicamentosa
Situation in which a patient reacts to a medication of the preservatives contained within an ophthalmic preparation
Tilted disc
Situs inversus, fundus ectasia and myopia and VF defect
Sattler's layer
Smaller vessels in choroidal stroma. Chris sattler was a small dude
When a blood vessel becomes ruptured due to trauma or injury, what is the body's first response to prevent blood loss
Smooth muscle contraction in the wall of the blood vessel
A ray of light traveling in water (n=1.33) strikes a flat, transparent surface (n= 1.59) at an angle of 32 degrees from the normal. What is the angle of refraction?
Snell's law of refraction states that when light travels through a material that possesses an index of refraction greater than 1.0, the light rays change direction and become bent (or refracted). Snell's law is depicted as the following: n sin i= n' sin i' where n= the index of refraction of the first medium, i= the angle of incidence, n'= the index of the second medium, and i' = the angle of the refracted ray. All angles are measured with respect to the normal, which lies perpendicular to the interface between the different media. For the above example, 1.33(sin 32)=1.59 sin i', solving for i'= 26.31 degrees. It is important to commit the index of refraction of water to memory; it is 1.33.
Point notation calculation
Snellen denominator/6
What agent is primarily responsible for the viscosity of the vitreous
Sodium hyaluronate
Reflexive blinking is caused primarily by
Stimulation of the orbicularis and inhibition of the levator palpebrae superioris
A 47-year old man sustained orbital trauma and now presents with complaints of retro-orbital pain, impaired ability to move the eye, a droopy eyelid, and diplopia. These signs are most consistent with damage to which of the following structures? Superficial temporal artery Superior orbital fissure Stylomastoid foramen Internal auditory meatus
Superior orbital fissure The superior orbital fissure is a cleft between the lesser and greater wings of the sphenoid. Structures traveling through the superior orbital fissure include the oculomotor nerve (CN III), trochlear nerve (CN IV), abducens nerve (CN VI), lacrimal nerve, frontal nerve, nasociliary nerve, and the ophthalmic vein (superior and inferior divisions). These structures can be damaged when there is orbital trauma causing fractures through the floor of the orbit into the maxillary sinus. This leads to superficial orbital fissure syndrome (also known as Rochon-Duvigneaud's syndrome). Signs include paralysis of extraocular muscles, diplopia, ptosis, exophthalmia and decreased sensation of the upper eyelid and forehead. Vision loss or blindness implies a more serious injury involving the orbital apex (orbital apex syndrome). Tolusa-Hunt syndrome (THS) is an inflammatory condition within the cavernous sinus or superior orbital fissure causing damage to the structures in those regions. Signs are usually acute and unilateral at onset in adults and the most common presenting signs are pain and ophthalmoparesis. The internal auditory (or acoustic) meatus is a canal in the petrous portion of the temporal bone through which the facial (CN VII) and vestibulocochlear nerves (CN VIII) and the labyrinthine artery travel. Damage to these structures can result in deafness and facial muscle paralysis. Acoustic neuromas will commonly expand the internal auditory meatus and damage these structures. Other signs may include tinnitus or vertigo. The stylomastoid foramen is the termination of the facial canal between the styloid and mastoid processes of the temporal bone. The facial nerve and stylomastoid artery travel through this area. Damage to this area can result in facial drooping and paralysis. Bell's palsy (idiopathic facial nerve paralysis) is an inflammatory condition that may lead to swelling of the facial nerve in this region. The superficial temporal artery is a major artery arising from the bifurcation of the external carotid artery. The artery begins within the parotid salivary gland and passes over the zygomatic process of the temporal bone. It is often affected in cases of giant cell arteritis (which is also known as temporal arteritis for this reason). This condition is a vasculitis of the medium and large arteries of the head and is not necessarily restricted to the temporal artery. Temporal arteritis is seen predominantly in older patients and is characterized by fever, headache, sensitivity on the scalp, jaw pain, reduced visual acuity or vision loss, diplopia, and acute tinnitus. Due to potentially rapid progressive vision loss, this disease is a medical emergency. Treatment usually consists of high-dose corticosteroids.
T/F: Lyme can cause encephalitis + meningitis 1-3 months after bite
true
T/F: RD risk for retinoschisis is very low (~1%)
true
Ascension phenomenon
Technique to better visualize vitreal cells or suspended granules Ask pt to move eye rapidly then stabilize; watch for cells floating across SL beam
What part of the midbrain is responsible for integrating visual info?
Tectum
What does the prosencephalon form?
Telencephalon -> cerebrum Diencephalon --> thalamus, hypoth, epithalamus
age for teller acuity? cardiff? broken wheel
Teller - up to 12 mo Cardiff/broken wheel - up to 18 mo all 3 are FPCL
Which region of the optic disc is typically the LAST area to swell in cases of papilledema? Inferior All regions swell equally Nasal Temporal Superior
Temporal
T/F: both horizontals & PRs hyperpolarize in response to light
true
What region of the optic disc is typically the *last* area to swell in cases of papilledema
Temporal *thickest ares of optic nerve tissue tend to appear swollen first*
Why can't we see our retinal blood vessels?
The eye does not respond well to *low temporal frequencies*
T/F: both sclera & episclera are posterior to tenon's capsule
true
EBMD or map dot
Thickening of basement membrane and deposition of fibrillary protein and relative absence of hemidosmosomes
Meesman's
Thickening of basement membrane and intraepithelial cysts
T/F: dry eye causes lower pH than normal
false - HIGHER PH increased osmolarity increases pH
T/F: dazzle is still intact in pts suffering cortical blindness
true
How to sterilize something?
Through autoclave - 250F / 121C for 15 min
T/F: drusen become more apparent on FL angio
true
What conditions are associated with Euryblepharon
Strabismus Double row of meibomian glands Telecanthus
T/F: during accom, the anterior surface of lens moves forward while the posterior surface remains stationary
true
First order aberrations
Tilt or prismatic error
T/F: pre-chiasmal lesions respect the horizontal midline
true
T/F: retinoschisis causes an absolute field defect
true
T/F: retinoschisis is typically bilateral
true
Trachoma
Superior follicles, Herbert's pits, Arlt's line
How to minimize spherical aberration?
Spherical aberration can be minimized by decreasing the size of the aperture/pupil.
4th order aberrations
Spherical aberration, tetrafoil and oblique astigmatism
uncontrolled DM causes what RE shift
hyperopic, during periods of severe hyperglycemia -due to lens thickening + associated decrease in lens index
Carotid triangle
Sternocleidomastoid, omohyoideus, stylohyoideus and digastric. The common carotid, internal jugular and vagus nerve pass through here
what can a lens clock measure (5)
Spec lens: add, BC, potential warpage, amount of slab-off, nominal (approx) power. RGP: center thickness
When analyzing a gas-permeable lens, you measure base curves of 7.58 and 7.84 with a radiuscope, and -1.00 and -2.50 on lensometry. What type of toric gas-permeable contact lens design do you have? Back surface (base curve) toric Front surface (F1) toric Thin-flex Cylinder power effect (CPE) bitoric Spherical power effect (SPE) bitoric
Spherical power effect (SPE) bitoric In order to determine which design of toric gas-permeable contact lens you have once the lens has been analyzed, the difference in base curve (BC) values and contact lens power (CLP) readings must be calculated first. BC1 = 7.58 = 337.5/7.58 = 44.50 BC2 = 7.84 = 337.5/7.84 = 43.00 Change in BC = 1.50 D CLP1 = -1.00 CLP2 = -2.50 Change in CLP = 1.50 D The differences in base curves and contact lens powers for the above gas-permeable contact lens are equal (both 1.50 D), indicating that the design of the lens is a spherical power effect (SPE) bitoric type. If the change in BC does not equal the change in CLP, the lens type may either be a base curve toric or cylinder power effect (CPE) bitoric. The way to tell these two apart is that if 3/2 change in BC = change in CLP, then it may be considered a base curve toric.
T/F: trachoma causes PAN, small superior tarsal follicules, and mild superior pannus
true
Impetigo is a superficial skin infection that can be caused by which 2 of the following pathogens? (Select 2) Staphylococcus aureus Staphylococcus epidermidis Streptococcus pyogenes Haemophilus influenza Neisseria meningitidis Pseudomonas aeruginosa
Staphylococcus aureus Streptococcus pyogenes
Impetigo is caused by one of two bacteria
Staphylococcus aureus Streptococcus pyogenes
Hofstetter add estimation
Starts at 40-44 at +0.75 to +1.00. Range increases by +0.50 every five years after 40 til 55 when it only increases by +0.25
What brain space is continuous with the optic nerve?
Subarachnoid space
What is known as the immunologically active tissue in the eyelids
Submucosal layer of the conjunctiva
ICH
Sulfas and tamoxifen, along with CATS and steroids
Which of the following are branches of the external carotid? (Pick 3) Maxillary Artery Short Posterior Ciliary Artery Superficial Temporal Artery Supratrochlear Artery Supraorbital Artery Facial Artery
Superficial Temporal Artery Facial Artery Maxillary Artery
Blood supply to the fibers of the oculomotor nerve?
Superficial fibers (including pupillary fibers) are supplied by the pial blood vessels; internal fibers are supplied by the vasa nervorum
What structure acts a fulcrum to change the direction of the superior palpebral levator muscle from anteroposterior to superoinferior direction
Superior transverse ligament (Whitnall's ligament)
Increase IOP
Supine and nicotine
Internal elastic lamina
Supports the intima, it is the outermost layer of the intima and is the border between the intima and media
Goldmann applanation tonometer size is chosen based upon the principle that which two forces will cancel each other out and result in an accurate reading of intraocular pressure?
Surface tension of tear film and corneal elasticity
A patient presents with confluent facial redness over the cheek and nasal region and mild conjunctival injection. You suspect which of the following conditions? Basal cell carcinoma Systemic lupus erythematosus (SLE) Seborrhoeic dermatitis Rosacea
Systemic lupus erythematosus (SLE)
CREST sx - assoc w/ what systemic disorder, what are the sx
Systemic sclerosis (scleroderma) Calcinosis Raynaud's Esophageal dysmotility Sclerodactyly Telangiectasia
All of the following play a significant role in the innate immune system except for which choice? Neutrophils Anatomical barriers Antimicrobial peptides T lymphocytes Complement system
T lymphocytes
mediator of type 4 sensitivity rxns? ex?
T lymphocytes organ rejection, ppd
The opening of which channels is responsible for initiating the pacemaker action potential?
T type Calcium channels
Systemic conditions AW KCN? mnemonic?
T-DOME Turners Downs OI Marfans Ehlers Danlos
you want to get a better view of a peripheral lesion with 3 mirror. Which way do you tilt mirror? which way do you have patient look?
TILT AWAY from lesion LOOK TOWARD
A very inquisitive patient asks you, "What is the difference between a corneal dystrophy and a corneal degeneration?" Which of the following options is MOST often associated with a corneal degeneration? Usually a primary disorder Tends to be unilateral Usually symmetrical Generally located in the central cornea Usually inherited
Tends to be unilateral
What class of medications should be taken with an empty stomach
Tetracylines (short-acting)
What is the name for the phenomenon in which a flickering light that is 10 Hz is seen as brighter than a steady light (one that does not flicker) that possesses the same average luminance?
The Brucke-Bartley effect describes the fact that a flickering stimulus that is 10 Hz will appear brighter than a non-flickering light with the same average luminance. This fact also holds true for stimulus presentation duration. A light that is presented for 50 milliseconds will appear brighter than stimuli presented for longer or shorter durations. The Troxler effect occurs when the eye is fixated (although the eye is truly always moving) on a point in space and the surrounding background begins to blend together. There must be several factors that come into play in order for the Troxler effect to transpire. The best example of this phenomenon is the figure in which there are two squares that are superimposed. The smaller square is centered in the larger square and is slightly lighter than the larger surrounding square. The border between the squares is blurred, resulting in a distinction of the two squares based upon brightness alone. When fixating upon an X placed in the center of the smaller square, the border completely disappears as does the smaller square, resulting in the perception of one uniformly-colored large square. Some patients experience the Troxler effect while performing the FDT visual field and they report, especially during testing of the second eye, that the entire field appears to go gray. When this occurs make sure to inform the patient to blink.
A central retinal artery occlusion (CRAO) causes tremendous damage to the retina. How will the electroretinogram (ERG) of a person who has suffered a CRAO be affected? Both the a-wave and the b-wave will disappear The a-wave will remain while the b-wave will disappear The a-wave will disappear while the b-wave will remain Both the a-wave and the b-wave will remain
The a-wave will remain while the b-wave will disappear
What wavelength of light is most readily absorbed by the photopigment rhodopsin?
The absorption spectrum curve for rhodopsin shows peak absorption for wavelengths that are roughly 507 nm. This is determined by taking a sample of rhodopsin and projecting a fixed quantity of monochromatic light onto it and measuring the amount of light that is transmitted. Light that is not transmitted is absorbed; therefore the absorption curve and the transmitted curve are reciprocals of each other. The procedure is repeated with many different wavelengths. The wavelength that results in the greatest amount of absorption (or the least amount of transmitted light) is obviously the one that has the highest probability of absorption by rhodopsin. 555 nm is the peak sensitivity for photopic conditions.
Free radicals can cause severe damage to tissue. Which of the following electrolytes can function as an antioxidant in the aqueous?
The aqueous humor contains many electrolytes including Na+, K+ , Cl-, HCO3-, glucose, lactate, amino acids, and ascorbate. Ascorbate is found in high concentrations in the aqueous (20x greater when compared to the concentration found in plasma). Ascorbate can serve as an antioxidant to eradicate free radicals reducing potential damage from ultraviolet light. Interesting note: the aqueous humor and tears of uncontrolled diabetics display higher levels of glucose than those of non-diabetics.
Color vision deficits and their respective confusion lines can be plotted on a CIE curve. What is the locus of origin for all of the confusion lines for a deuteranope called? Neutral points The Planckian locus The copunctal point Complementary colors
The copunctal point
In order for emmetropization to occur, which of the following changes must occur as a child grows
The cornea and lens must both lose refractive power as the axial length increases
Margin reflex distance 1 is commonly utilized in evaluation of a ptosis
The distance between the upper eyelid margin and the corneal reflection of a penlight that the patient is viewing directly Average measurement = 4-4.5 mm
Where to measure distance prescription of a progressive?
The distance reference point/arc
In a fetus, what is the name of the blood vessel that shunts the majority of blood away from the liver, delivering it instead to the fetus' heart? The arterial duct The ductus venosus The foramen ovale The umbilical cord
The ductus venosus
The patient wishes to order a lens material that offers high oxygen permeability (Dk). For a gas-permeable lens, which of the following occurs as the oxygen permeability of the lens is increased?
The durability of the lens decreases.
Which of the following BEST describes the excitation and emission characteristics of fluorescein?
The excitation peak is 490nm; the emission peak is 530nm
A spectacle lens has total spectacle mag of 1.35. What does this mean?
The image is 35% larger with glasses than without. (we want Ms to approach 1) Make lens thinner => Ms would approach 1 => total mag would get smaller.
The ligaments that suspend the lens (zonules) are embryonically derived from what structure? The lens epithelium The lens capsule The tertiary vitreous The primary vitreous
The lens capsule
The synthesis of testosterone by cells in the testicles is governed by which of the following hormones secreted by the anterior pituitary? Oxytocin The luteinizing hormone (LH) The gonadotropin-releasing hormone (GnRH) Aldosterone
The luteinizing hormone (LH)
The synthesis of testosterone by cells in the testicles is governed by which of the following hormones secreted by the anterior pituitary? The gonadotropin-releasing hormone (GnRH) Oxytocin The luteinizing hormone (LH) Aldosterone
The luteinizing hormone (LH)
The blood-aqueous barrier is formed by tight junctions between which cells of the ciliary body? The stromal cells The circular cells The pigmented epithelial cells The non-pigmented epithelial cells Basal laminar cells
The non-pigmented epithelial cells The cells of the non-pigmented epithelium have many different attachment sites to each other to ensure that proteins and other macromolecules do not enter. The side walls of the cells are connected via desmosomes. The superior portion of the cell's lateral wall towards the apex are firmly joined by a connection termed zona occludens. The non-pigmented epithelial cells and the epithelial cells are attached to each other by desmosomes and puncta adherens to ensure that the layers are not easily separated.
Which of the following structures serves as the strongest attachment point of the vitreous? The macula The ora serrata The optic nerve head Blood vessels
The ora serrata The ora serrata, which also serves as the anterior vitreous base is the strongest point of attachment of the vitreous. The second strongest point of attachment is the optic nerve head. A detachment of the posterior hyaloid from the optic nerve head results in a posterior vitreal detachment (PVD) commonly reported in the elderly as the sudden appearance of a large floater that is oval or circular in shape (Weiss ring). The macula is the third strongest point of attachment, followed by the blood vessels.
Enzymes function best within a certain pH range. In order to maintain optimum conditions, bicarbonate is secreted into the small intestine to neutralize hydrochloric acid. Bicarbonate is secreted by which organ? The liver The pancreas The stomach The gallbladder
The pancreas
Krukenburg spindles
Triangular pigment dusting on endothelium due to pigmentary dispersal syndrome
A sign that gives the illusion of a person drinking a soda through the use of apparent motion caused by flashing lights is an example of which of the following? Mach bands The phi phenomenon After-images The Troxler effect
The phi phenomenon
Electroretinograms (ERGs) are used to help determine if certain cells of the retina are deficient. Which cells are responsible for producing the A-wave? The photoreceptors Retinal pigment epithelial cells Ganglion cells Mueller cells Bipolar cells
The photoreceptors
The fact that 100 quanta of 507 nm and 200 quanta of 580 nm produce the same effect on rhodopsin is known as which of the following? A duplex retina The principal of univariance Mesopic conditions The Purkinje shift
The principal of univariance
What happens if an atom of light has the same frq as the media it enters? What if it's not the same?
The same - light energy will be absorbed and converted to thermal energy Different - electrons vibrate, then re-emitted as a light wave (transmitted if transparent, reflected if opaque)
What modification can be made to the contact lens in order to decrease the occurrence of dimple veiling
The treatment of choice is decreasing the optic zone diameter to allow for better tear flow that may have been impeded by a tight mid-peripheral junction of the optic zone and intermediate and peripheral curvatures of the contact lens. Dimple veiling will often resolve with a flatter lens, decreasing the overall diameter of the lens, or decreasing the optic zone diameter.
If the change in BC does not equal the change in CLP, the lens type may either be a base curve toric or cylinder power effect (CPE) bitoric. How to tell the difference?
The way to tell these two apart is that if 3/2 change in BC = change in CLP, then it may be considered a base curve toric.
Why don't acid injuries penetrate further than superficial tissues?
They bind and coagulate surface proteins --> bars further penetration
trichiasis = districhiasis = poliosis = madarosis =
Trichiasis - turning inward of eyelashes Distichiasis - two rows of eyelashes (occurs when 2nd row arises near meibomian gland openings) Poliosis - whitening Madarosis - lash loss
Minimum antireflective coating thickness equation
Thickness = wavelength/(4 x index of coating)
Minimum antireflective coating thickness calculation
Thickness = wavelength/(4n)
Inner limiting membrane of Elschnig
Thin layer of astrocytes at the optic disc
Ocular findings that have correlation to Alzheimer's
Thinner RNFL Cupping (reduction/degen of neurons) Lenticular amyloid deposits on equatorial zone
What happens to epithelial cells at the cone apex in KCN?
Thins Changes shape - obliquely elongated and stretched
Coma is known as
Third-order aberrations
What GL med is LEAST effective at stabilizng an IOP spike that happens at night
Timolol bc it works via decreasing cAMP in ciliary epi (less aqueous) CAIs still good at decr AQ production bc CA component of system still remains active at night alphagan also decr AQ production but studies show it's still active at night, prob due to its dual effect at also increasing uveoscleral outflow
Which of the following glaucoma medications has the FASTEST PEAK onset of action? Latanoprost Timolol maleate 0.5% Bimatoprost Brimonidine tartrate 0.1%
Timolol maleate 0.5%
Stopped on 9/29
To be continued..
What is the equivalent decimal acuity
To determine the decimal equivalent simply divide the numerator of the Snellen fraction by the denominator
BP cuff that's too small --> false ______? too large?
Too small --> false high Too large --> false low
Typical ophthalmic medications prescribed for use during the first week after undergoing LASIK include which three of the following? (Select 3)
Topical steroid, topical antibiotic, and artificial tears
You are designing a rigid gas-permeable (RGP) contact lens for your patient who presents with keratometry reading of 43.75 x 40.50 @ 100, and manifest refraction of +1.00 -4.50 x 100. With a spherical RGP diagnostic lens placed on the eye, the over-refraction is -0.50 -1.50 x 100. Which of the following RGP lens designs is MOST appropriate for this patient? CPE Bitoric Front Surface (F1) Toric SPE Bitoric Toric Base Curve Spherical
Toric Base Curve Both corneal and residual cylinders are the same axis, and the over-refraction cylinder amount is about 1/2 of the amount of the corneal toricity.
Best way to determine if a patient's corneal thickness is adequate for LASIK
Total pachymetry - (flap thickness + ablation depth) = at least 250 microns
An 18 year-old female presents to your office with a corneal abrasion that occurred when she was removing her contact lens. Which of the following cranial nerves is responsible for the reflex tearing that she is experiencing as a result of the corneal abrasion? Facial nerve Trigeminal nerve Oculomotor nerve Trochlear nerve Abducens nerve
Trigeminal nerve
Lipemia retinalis is a retinal finding associated with markedly high levels of
Triglycerides (greater than 1000) *associated with pancreatitis*
True membrane v pseudomembrane
True membrane - infiltrates the epithelium; if try to peel --> bleed Pseudomembrane - coagulum is just deposited on the surface of the epith
T or F. abducens (6th cranial nerve) is the most commonly affected cranial nerve in cases of elevated intracranial pressure due to the presence of a space-occupying intracranial tumor.
True. An abducens nerve palsy occurs due to the fact that an elevation of intracranial pressure will cause the 6th cranial nerve to be stretched and compressed as it courses over the bony petrous tip of the skull, leading to either unilateral or bilateral dysfunction.
Serotonin precursor
Tryptophan, not a catecholamine
In AS - damage is at the level of what?
Tunica intima
Neutral density filters and how they tell organic vs functional reduced visual acuity.
Two neutral density filters (Kodak Wratten filter 96, ND2 and ND0.50), when placed before an eye with a poor acuity that is of organic etiology, will result in a significant reduction of acuity. If the visual loss is attributable to functional causes (strabismus), the acuity will be either minimally affected, will improve, or will remain unchanged.
Dimple veiling - possible tx options + best tx option
Tx of choice - decrease OZD Decrease OAD Flattening BC
Turville Infinity Binocular Balance
Type of binocular refraction where neither eye is occluded and a septum is placed between the patient and visual acuity chart so the central fusion of the eyes is eliminated but peripheral fusion is maintained *works well with patients with strabismus, high phorias and amblyopia*
Insulin binding
Tyrosine kinase is activated
how many lashes on UL and LL?
UL: 100-150 LL: 50-75
Gout is associated with accumulation of?
URIC ACID - if not elim. in urine will form crystals in joints causing pain mostly in big toe, knee, and ankle
crosslinking uses what? min thickness?
UVA light + riboflavin must be >400 microns to continue with uve light exposure after using riboflavin
Levator function test of under ____ indicates a problem with function
Under 12mm (normal is 15mm)
Up to what percentage of patients with PDS will develop glaucoma?
Up to 50%
Y sutures in the fetal nucleus of the crystalline lens
Upright Y in anterior suture Inverted Y in posterior suture
how to find the critical angle for light traveling in water that reaches a water-air interface?
Use Snell's law, with theta2 = 90. 1.33 sin (critical<) = 1.00 sin(90)
JND
Use the best visual acuity of the two eyes and it has to be at 20 feet.
Fluorophotometry
Used to measure rate of aqueous formation
EOG
Uses electrically positive cornea and negative back of the eye to get resting potential. Done in dark adapted and light adapted
What are the advantages of potassium-sparing diuretics
Utilized in the treatment of edema Used to treat hyperaldosteronism
What part of the vestibular apparatus plays an important role in balance and spatial orientation
Utricle
Pons nuclei
V, VI, VII and VIII. Think midbrain, pons, medulla
Cross cylinders (+-0.50 D) are placed before a patient's eyes while the patient views a near grid with horizontal and vertical lines. The plus meridian of the cross cylinder is vertical. Assuming that no add power is needed for this patient, which set of lines (horizontal or vertical) appear the most clear?
VERTICAL The alignment of the JCC means that the horizontal line focus of the Conoid of Sturm will fall before the vertical line focus. If the vertical line appears brightest, the patient has been able to accommodate sufficiently and does not require an add. On the other hand, if the horizontal line appears brightest, one should add +0.25 D increments until the images become identical or the vertical lines appear brightest.
what med besides NSAID+coumadin can cause subconj heme
VIAGRA
poliosis, white eyebrows/hair & alopecia are common in what disease
VKH syndrome
VDRL, RPR and FTA-ABs stand for
Venereal disease research lab Rapid plasma reagent card test Fluorescent treponemal AB absorption FTA = Forever RPR = right now (VDRL/RPR = + in active syph only)
Dural sinuses
Venous channels that carry blood from brain to heart
A pt with WTR cyl will have what bowtie configuration on topography imaging
Vertical bowtie (bowtie = steeper meridian)
A 24-year old female patient is seen at your office and reports that her eyes have been red for a few days. Biomicroscopy reveals bilateral diffuse superficial punctate keratitis (SPK) that stains with sodium fluorescein with no mucopurulent discharge. Based ONLY upon the corneal staining pattern, what is the MOST likely origin of her condition? Dry eyes Foreign body Viral Bacterial
Viral
Diffuse SPK
Viral
Parietal lobe lesion
Visual neglect on the contralateral side
Riboflavin refers to which of the following vitamins? Vitamin B2 Vitamin A Vitamin E Vitamin C
Vitamin B2
AREDS I formula
Vitamin C: 500mg Vitamin E: 400IU Beta-carotene: 15mg Zinc (as zinc oxide): 80mg Copper (as cupric acid): 2mg AREDS 2 added luetein, zeaxanthin, DHA + EPA
what qualifies as oblique cyl
WTR = x180 +/- 30* ATR = x90 +/- 30*
Conjugation
When bacteria have sex
When to use chocolate agar?
When suspect Neisseria (gonorrhea), Haemophilus, Moraxella species All of these are G-
Capillary hemangioma
Will blanch with pressure and with valsalva maneuvers
CL warpage
Will decrease toricity and maintain the same apical relationship because the average is the same
Long term lid attached RGP
Will get keratoconus topography due to superior flattening and inferior steepening
Dimple veiling
With an RGP it is usually due to air bubbles. With soft lenses it is usually due to mucin balls, lipids and proteins
Classic migraine
With aura, starts central for awhile then quickly goes through periphery due to large amount of occipital cortex being devoted to the macula and central vision
A protanope has a neutral point of 492 nm. Light with a wavelength of 502 nm will MOST likely be perceived as what color by this individual? Red Yellow Green Blue
Yellow In protanopes, wavelengths above the neutral point are perceived as various hues of yellow, and those below the neutral point are seen as blue that increases in saturation towards the shorter wavelengths.
Frame ANSI marks
Z87-2 = High impact and high mass velocity tests + = High impact V = photochromic S = special (glass blowers.)
ANZI standards: what marking is required on frame to qualify as safety
Z87-2 and the manufacturer's mark on front of frame + both temples
Microtropia
a small angle heterotropia of less than 5-10 prism diopters, usually associated with harmonious anomalous retinal correspondence, partial stereopsis, and mild amblyopia. Microtropias are typically esotropias but may also present as an exotropia or vertical microtropia (much less common).
what are proteoglycans
a sulfated GAG bound to a protein
what is Thayer-Martin agar used to culture
a type of chocolate agar used for N. gonorrhoae
what is hyperacuity
ability to sense directional relationships (ie. whether 2 lines are parallel) -ability very good (threshold is several arc-secs) result of HIGHER CORTICAL PROCESSING
firs cell in visual pathway to undergo an AP
amacrine cells (only amacrines + GCs produce APs) both horizontals & PRs hyperpolarize in response to light
which topical ABs are known for causing SPK they cause
aminoglycosides partially bc they have BAK (but lotsa things have BAK, many of the GL drugs)
Functional residual capacity
amount of air in the lungs following a tidal exhalation (expiratory reserve volume plus residual volume)
anatomical vs physiological origin of SO
anatomical: lesser wing of sphenoid and CTR physiological: trochlea
Anomalous trichromats
are in possession of all three photopigments, but the absorption spectrum of one of the pigments has been shifted. For a protanomalous trichromat, the spectrum for erythrolabe is shifted towards the shorter wavelengths. A deuteranomalous trichromat displays a shift of the maximum sensitivity of chlorolabe towards the longer wavelengths.
what part of nephron is never permeable to water
ascending limb of Henle DCT can be perm to water only via ADH proximal tubule => Na out; water, chloride, bicarb follow it out.
the 1* antioxidant in the cornea + anterior seg =
ascorbic acid -high conc in AQ and corneal epi -responsible for complete absorp of UVC, and signif attenuation of UVA+UVB
ideal injection site for FA angio
antecubital vein (inside of arm above elbow joint) tourniquet 6" above, make a fist Fl gets to eye within 15 seconds if antecubital can't be accessed, then they use either vein on back of hand or thumb side or wrist
avg central radius of anterior & posterior cornea
anterior = 7.8 mm posterior = 6.5 (steeper)
What shapes are the anterior and posterior human cornea respectively?
anterior = elliptical with its long axis HORIZONTAL posterior = spherical
which Y suture is upright
anterior = upright posterior = inverted
episclera contains what blood supplies
anterior ciliary & posterior ciliary arteries => superficial + deep episcleral venous plexi
bulbar conj & CB both receive part of their blood supply from which artery
anterior ciliary.
how thick is descemets at birth? how does it change?
anterior descemets forms in utero = 3 um posterior 2/3 forms after birth, allows it to thicken to 20-30 um with age
embryotoxon = when are they considered abnormal?
anteriorly displaced Schwalbes 15% of pts have them abnormal when AW prominent iris strands (ie. Axenfelds anomaly - 60% GL risk)
Phenytoin is Rxed for? ocular AE?
anti-anxiety AE nystagmus + diplopia 2* to EOM palsies (does not cause mydriasis like the antidepressants/ TCAs/SSRIs)
what type of drug is chlorpheniramine?
antihistamine like benadryl MYDRIASIS
medicines AW dry eye
antihistamines BBs BC/HRT accutane SSRI's
benzos are Rxed for? AE?
anxiety sedation, anesthesia
eye using a hand magnifier: what is aperture stop? field stop?
aperture stop = pupil field stop = mag lens brightness of system depends ONLY on aperture stop (pupil size.)
CB apex points in what direction? is continuous with what structure?
apex points posteriorly apex continuous with choroid CB = 6 mm wide band
MAR is typically measured in
arc-minutes (1/60th of a degree)
avg LASIK flap thickness? how much must remain under flap after surg?
avg flap = 160-200 250 must remain
Which of the following wavelengths of visible light has an increased association with the development of macular degeneration? a. 485nm-510nm b. 415nm-455nm c. 520nm-555nm d. 570nm-620nm
b. Recent studies have demonstrated a correlation between blue-violet light that lies within the range of 415nm-455nm and the development of macular degeneration. Excessive exposure to light that falls within this bandwidth is associated with death of the retinal pigment epithelial cells. However, blue-turquoise light (465-495nm) does not appear to possess detrimental effects to ocular health. Blue-turquoise light is important in activation of the pupillary reflex as well as management of the circadian sleep/wake cycle. There is increasing evidence that compact fluorescent lamps, LED lights as well as sunlight all transmit blue-violet light, which over time may be linked with retinal damage.
Central serous retinopathy (CSR) is associated with an acute decrease in vision along with central distortion. The condition usually occurs unilaterally. Which gender and age group tends to have the highest incidence of CSR? a. Females; ages 10-20 b. Males; ages 30-50 c. Males; ages 50-70 d. Females; ages 20-40
b. Males; ages 30-50 CSR is more commonly seen in middle-aged males under high-stress, high anxiety, or with type A personalities. This condition causes fluid to leak from the choriocapillaries into the subretinal area, causing a serous detachment of the neurosensory retina. There is an associated loss of the foveal reflex, a hyperopic shift, a potential relative scotoma, and metamorphopsia. Flourescein angiography will reveal hyperfluorescence that appears like a smoke-stack. Evaluation of the posterior pole will typically display a blister-like elevation of the neurosensory retina. The patient is monitored monthly and intervention is rarely required, as most cases of CSR will resolve within roughly 6 months.
A Giemsa stain that reveals PMNs would indicate
bacterial infection (Giemsa + multinucleated giant cells = HSV)
Blepharochalasis =
baggy lids from recurrent swelling in younger to middle aged pts -may mimic ptosis Tx = cool compresses
lid telangectasia is AW 2 diseases:
basal cell ocular rosacea
why is mycoplasma resistant to penicillin
bc it has no cell wall for it to attack!
HLA-B51 =
behcets
what 2 diseases can cause severe non-granulomatous anterior uveitis often with hypopyon
behcets reiters
Meige syndrome =
benign essential bspasm plus lower facial abnormalities (difficulty chewing, opening mouth etc.)
acoustic neuroma =
benign tumor of myelin-forming Schwann cells of the 8th CN -slow growing (years) no obv Sx Sx = hearing loss, balance issues, vertigo, feeling of pressure in ear, tinnitus compress CN 5 => less corneal sensitivity can compress 6 too can elevate ICP if very large (more rare)
What crystallin protein is found in the greatest concentration in the human lens?
beta
ocular dominance: columns 2 and 3
binocular but dominant for contra eye (1 = contra only)
how does caffeine work
blocks adenosine adenosine signals body to shut down when fatigued caffeine is AW elevated BP and osteoporosis
Cyclosporine A MOA? used for?
blocks cytokine production prevent corneal graft rejection Tx endogenous uveitis, Behcets sympathetic ophthalmia SEVERE VKC paracentral corneal ulcers in RA pts
During ocular development, the pupillary membrane consists of
blood vessels!
causes of Salzmann's nodular degen? appearance?
blue-gray stromal opacities chronic keratitis dry eye trachoma
AE of Methotrexate
bone marrow dep hepatic cirrosis teratogenesis death used for SEVERE psoriasis or RA, & life threatening cancer. due to the AE its reserved for severe conditions where other Tx have failed
chloramphenicol's scary AE
bone marrow depression can lead to blood dyscrasias (eg. aplastic anemia)
what 2 corneal layers dont regenerate
bowmans + endo
A pt with x45 cyl will have what bowtie configuration on topography imaging
bowtie along 135* meridian (bowtie = steeper meridian)
which plaque is most serious threat to vision
calcific (large, common culprit for CRAO)
band keratopathy is deposits of? which layer? 4 conditions?
calcium deposits (swiss cheese on anterior Bowmans chroic inflam (JIA, iritis) gout, hypercalcemia, renal failure
Asteroid particles are comprised of ? Sx?
calcium-phosphate soaps no Sx, otherwise normal, no floaters or vision loss
what is a dimorphic fungus
can alter forms in presence of a temperature change can change from single-celled yeast form to mold/mycelial (multi-cell form) room temp = mold body temp = yeast
pouting puncta
canaliculitis
what fungi is classically AW fungal ulcers AW chronic keratitis
candida when do fungal ulcers occur? 1. chronic keratitis = candida (longstanding DES, exposure ktopathy etc) 2. veg matter trauma (must common) -aspargillus + fusarium 3. immunocomp or severely debilitated -candida also filamentous fungi = asp + fusarium candida is non-filamentous
what happens to PR cell when light isomerizes 11-cis to all-trans
cascade leads to closure of a cGMP-gated cation channel => hyperpolarization of PR cell then all-trans-retinal is reduced to all-trans retinOL => 11-cis retinol => 11-cis retinAL then travels back to outer seg + attaches to an opsin. ready again.
Bartonella henselae is responsible for
cat scracth disease
list all the bacteria that can cause oculoglandular syndrome
cat-scratch disease, tularemia, syphilis, tuberculosis, sprotrichosis, mononucleosis, coccidioidomycosis (soil fungus - rare in kids, more in gardeners), sarcoidosis, Hansen's disease, mumps, actinomycosis, Listeria and Herpes simplex.
most common benign ORBITAL tumor in adults
cavernous hemangioma -they typically arise directly behind the eye (in circle of zinn) => progressive, unilateral proptosis CAPILLARY hemangiomas = msot common benign orbital tumor in kids
45 yo man has loss of corneal sensation, cant abduct, & tilts head toward left shoulder. No facial asymmetry or hearing difficulties. where is most likely site of lesion?
cavernous sinus (3, 4, 6, V1, V2, symps) V1 - corneal sensation CN 4 - head tilt CN 6 - abduct hearing+facial asymmetry would be CN 7 which is unaffected.
what is orthograde degen
cell body dies, so then axon dies (ex. in PRP which destroys GCs, but then can lead to disc pallor from axon loss)
3 drug classes that are AW C. diff infections
cephs/pens + clindamycin C. diff = diarrhea + pseudomembranous colitis
electroretinogram (ERG) is helpful in the detection of
certain retinal disorders such as color blindness, night blindness, and other retinal degenerations.
pts with pigmentary GL have what type of AC configuration
characteristically deep
What drugs cause folic acid deficiency?
chemo, methotrexate
name 2 obligate intracell parasites
chlamydia + rickettsia rickettsia = gram neg = rocky mtn spotted fever via tick bites Tx = doxy classic triad of Sx = fever, HA + rash
name 2 drugs that may cause color vision defects
chlorpromazine isoniazid
Synchysis Scintillans' golden brown refractile crystals are
cholesterol usually caused by previous pathology - chronic uveitis, vitreous heme and/or trauma (unlike asteroid hyalosis which is idio)
What are Dalen-Fuchs nodules?
chorioretinal lesions that are typically a/w Vogt-Koyanagi-Harada syndrome and sympathetic ophthalmia
AQ is made by plicata or plana
ciliary processes of pars PLICATA
limbic system =
cingulate gyrus fornix hypothalamus hippocampus septal areas limbal cortex amygdala
role of pineal gland
circadian rhythms
spectacle prescription: -1.00 -2.00 x 080 Keratometry readings: 43.00 @ 170 / 42.50 @ 080 Diagnostic lens parameters: 7.94 (42.50) / -2.00DS What is the predicted over-refraction? -1.00 -3.00 42.50 43.00 --> leaves 0.50 corneal astig which means there is 1.50 of lenticular astig -2.00 -2.00 --->
corneal astigmatism is calculated as 0.50 D (axis 080). The tear lens between the corneal surface and contact lens should theoretically correct that amount of anterior corneal astigmatism, leaving 1.50 diopters of residual (lenticular) astigmatism, which is enough to reduce the patient's acuity if left uncorrected. Therefore, the expected residual cylinder, the spherical component of the spectacle prescription, and the power of the diagnostic contact lens can be taken into consideration to provide a predicted over-refraction of +1.00 -1.50 x 080.
flour dust deposits in deep stroma =
corneal farinata
What structures does the neural crest give rise to?
corneal stroma, corneal endothelium (inc Descemet's membrane), most of the sclera, trabecular structures, uveal pigment cells
2 types of nephrons =
cortical & juxtamedullary cortical are shorter, & their Henles go into medulla but only to shallow extent juxtamedullary = much longer loop that penetrates deep into medulla. JXM's control urine conc. medulla = innermost portion of kidney (inside cortex, where renal corpuscles are) -all = surrounded by capsule.
Cryptococcus neoformans causes
cryptococcosis (potentially fatal FUNGAL infection)
homocystinuria is caused by? inheritance? manifestations?
cystathionine synthase deficiency inferior sublux GL (from pupil block or lens sublux into AC) similar to marfans (tall) but these pts are below normal intelligence + stiff joints
Cysticercus cellulosae causes
cysticercosis (infection that causes cysts throughout the body)
Cosopt =
dorzolamide (CAI) + timolol
which nasolacrimal problem is most painful
dacryocystitis HUGE PIMPLE over lacrimal sac region epidermidis/aureus in adults, H flu in kids
MOA of Ca channel blockers
decr HR by decreasing Ca levels within myocardial cells
ERG of a pt with PDR will show
decrease in amps of photopic + scotopic B waves
PRP may cause what visual Sx? color?
decreased peripheral vision + night vision -blue/yellow color defect color defect used to be much worse bc argon laser has both short + medium wavelengths (short damages more) -now we filter out the short during PRP
Niacin (vitamin B3) has what effect on cholesterol
decreases LDL and VLDL
MOA of amantidine? Rxed for
decreases viral replication by preventing uncoating of viral RNA particles within host cells via inhibition of M2 proton ion channels
Megalopapilla
defined as enlarged optic discs not associated with any other morphological anomalies. There are two phenotypic features of this condition. Type 1 features an abnormally large disc, a high C/D ratio, disc surface pallor, round or horizontally oval-shaped cup, absence of nasalization of vessels at the point of origin, and is usually bilateral and congenital. Type 2 is less common. It is usually unilateral with the cup displaced towards the top, obliterating the adjacent neuroretinal rim. Visual acuity is typically not affected. DM: DD Ratios less than 2.2 signify megalopapilla
DM:DD ratio
defined as the disc-macula:disc diameter (DM:DD) ratio. It is the ratio of the horizontal distance between the center of the optic disc and the macula to the mean diameter of the optic disc. In this case, the right eye measurements used were ~6cm/2.5cm=2.4; the left eye measurements used were ~7cm/4.2cm=1.67.
Emphysema
destruction of alveolar walls leading to decreased gas exchange; commonly caused by smoking
uncal herniation will affect what first
dilate pupil (pupil fibers outside) THEN EOMs will be affected (CN 3 palsy - down+out)
how does adies respond to near vs light
dilated irregular pupil. slow near response minimal light response over time, an Adies may become MIOTIC!
most common initial ocular sign in a pt with an acoustic neuroma =
diminished corneal sensitivity
MOA of chlorhexidine? use?
disinfectant a biguanide that binds to bacterial cell membs => leakage of contents
each 20/20 letter ST an angle of __ at 20 feet Each distinct bar making up the letter ST __
each letter = 5 arc-min each bar = 1 arc-min (E is made of 5 bars)
most common ocular asssociations with marfans
ectopia lentis hypoplasia of pupil dilator angle anomalies high myopia RD KCN
how do eyelids improve optics
enable regular moist corneal surface
brown pigment deposits in what layer in KCN
epi
which layer of cornea can store glycogen for anaerobic times
epi
lamellar kplasty replaces what
epi & partial thickness of stroma
which corneal layer consumes the most O2? which corneal layer's individual cells comsume the most o2 each?
epi = 40% stroma = 39% endo = 21% but ENDO consumes the most O2 per cell.
cause of brown depsoits in epi vs. deep stroma
epi = amiodarone, fabrays, tamoxifen, chlorpromazine, chloroquine indomethacin deep stroma = chrysiasis (gold salts for RA)
corneal filaments =
epi cells + mucus
RCE happens in pts with __ dystrophies
epithelial (EBMD)
what is the exit pupil of a telescope? galilean vs keplerian?
exit pupil = image of the entrance pupil (objective lens) as viewed thru ocular. Galilean exit pupil = virtual + inside tscope virtual = WITH motion Keplerian = real exit pupil (against motion)
3 most common causes of non-rheg RD
exudative ARMD PDR (preretinal neo pulled off) Choroidal melanoma
most likely etiology of a cavernous sinus thrombosis
facial infection most commmonly nasal, or around nose/eye S aureus is most common
Optic pit
fairly rare congenital condition in which there is a round or oval depression within the optic nerve. The condition is usually unilateral and the affected area generally appears darker or gray on ophthalmoscopy. Pits are most frequently located temporally but may be seen centrally or in other locations. The disc margin remains unaffected. Patients are asymptomatic and visual acuity remains normal as long as a serous detachment of the macula does not occur. There may be an associated area of peripapillary atrophy adjacent to the pit. Commonly, the nerve possessing the pit is larger than the nerve of the contralateral eye. Cilioretinal arteries are frequently observed in eyes with optic pits. Optic pits are congenital in nature and occur secondarily to a deficiency within the lamina cribrosa allowing for dysplastic retina to enter the defective area.
An electrooculogram (EOG) can be helpful for
for confirming diagnoses of retinal diseases such as Best's Disease, and also for use in evaluating eye movements.
most common cause of unilateral proptosis: A. CCF B. hyperthyroid C. tolosa-hund D. sinusitis
hyperthyroid = most common cause of unilateral AND bilateral proptosis
(+)Watzke-Allen sign indicates
full thickness macular hole typically not apparent until stage 3 and beyond
2 conditions AW infant cats
galactosemia rubella
mag of a galilean telescope is + or -? mag of an astronomical telescope =?
galilean (+) - virtual upright astro = keplerian = (-) - real + inverted
the enzyme fructose 1,6,biphosphatase is used in
gluconeogenesis
Colchicine is used to Tx (2)
gout Behcet's
What causes chronic bronchitis
hypertrophy of mucus-secreting glands in bronchioles
What is minimum blank size
he smallest diameter of lens that can be used to engineer a person's ophthalmic prescription.
ribavarin treats
hep C
what issues do aphakes have
high hyperopia monocular correction => anisekionia + diplopia binocular correction => pincushion, reduced VF, ring scotoma ("jack-in-the-box" effect - stimuli disappear & reappear briefly as they pass in & out of the scotoma) + increased convergence demands from the large BO prismatic effects of a high (+) calculate mag for aphakes with the telescope formula M = -F1/F2
HLA-B7 and HLA-DR2 =
histo + AMPEE (acute multifocal placoid pigment epitheliopathy)
Reed-sturnberg cells =
hodgkins lymphoma large binuclear or multinuclear cells, abundant pale cytoplasm, nuclei w/ reticulated chromatin + prominent macs. RS cells induce accum of benign inflam cells => node enlargement
Lens subluxation happens in what direction fo homocysteinuria vs. marfans
homo: DOWN+IN marfans: UP+IN
horizontal corneal striae are AW? vertical?
horizontal = descemets = haab's striae (GL) vertical = deep stroma = KCN (Vogt's striae)
Haabs striae = horiz or vert? what layer?
horizontal breaks in Descemets congenital GL
where does symp pathway begin
hypothalamus
When can principal planes be located outside of the thick lens itself
if front surface is very convex
True/False. Intravitreal fluorescein angiography (IVFA) is helpful in cases of presumed ocular histoplasmosis
if the diagnosis is uncertain, or to detect and properly treat a choroidal neovascular membrane (CNVM).
type 3 sensitivity rxns = mediator?
immune complex formation (SLE, arthus rxns, serum sickness)
oral cyclosporine is used for
immunosupp prevent organ rejection
azithioprine is used for
immunosuppressant -RA, joint pain -prevent organ rejection
Niacin (vitamin B3) is important how biochemically
important cofactor for NAD and NADP (decreases LDL and VLDL)
role of megakaryocytes? location?
in bone marrow produce thrombocytes (required for clotting)
Ferry's line is found where
in front of a filtering bleb
yellow tinted lenses are useful when
in low light bc they enhance contrast
STEEPENING LENSES IF FIT TOO LOOSELY =
increase the optic zone, increase the overall diameter (OAD), narrow the peripheral curve system, or steepen the peripheral curve system.
what increases during accom? what decrease?
increases = lens thickness, anterior + posterior lens curvature (anterior increases more) decrease = lens diameter + IOP
mech of digoxin
increases heart contractions by INHIBITING Na/K/ATP pumps => more intracell Ca => more contractions.
chloroquine use, risk for retinopathy increases when?
increases under dosages greater than 3.5mg/kg/d or a cumulative dose of greater than 460g.
V2 is comprised of which 2 nerves
infraorbital & zygomatic nerves zygomatic = lateral structures (like lateral LL)
MOA of foscarnet & famciclovir
inhibit DNA polymerase
ACE inhbitors conversion of what? leads to?
inhibit conversion of Ang1 to ang2 => decr periph resistance + reduced BP
MOA of statins
inhibits HMG-CoA reductase
methotrexate MOA
inhibits dihydrofolate reductase => disrupts formation of DNA, RNA + other key cell proteins
streptomycin inhibits translation or transcription? eukaryotes or prokaryotes?
inhibits translation in prokaryotes (streptomycin, gentamicin, tobramycin all inhibit 30S subunit)
SPCAs are branches of
internal carotid
retractor dehiscence causes
involutional ectropion
bells palsy affects __lateral side of face & is a __ motor neuron lesion
ipsi lower (stroke = contra/upper & spares forehead)
Which of the following structures would NOT be visible in a patient with Grade 2 narrow angles? (Pick 3) Peripheral iris Scleral spur Trabecular meshwork Ciliary body
iris, CB + TM
where is a Hudson-Stahli line found? made of?
iron junction of lower + middle third of cornea (where lid closure occurs on blinking)
what are guttata
irregular excrescences of Descemets memb -typically seen in center, not periph fuchs = guttata + stromal AND epi edema.
MOA of botox
irreversibly binds to presynaptic cholinergic nerve terminals
Presumed ocular histoplasmosis
is a retinal condition that most commonly presents in patients who have, at one time or another, lived in the Ohio-Mississippi River Valley. Diagnosis typically occurs when patients are between 20-50 years old. Patients usually present with a classical clinical triad of retinal findings that includes histo-spots, a macular choroidal neovascular membrane (CNVM), and peripapillary changes. Histo-spots are identified as punched out, yellow-white lesions that are usually less than 1 mm deep. These lesions may contain pigment clumps either in or at the area of the margins, and are typically observed in the region of the peripheral fundus. The second feature of the classic POHS triad is the presence of a macular CNVM, which appears as a gray-green lesion beneath the retina, and is commonly associated with a focal detachment of the sensory retina, subretinal fluid/exudates, or a pigment ring, which may evolve into a disciform scar. The third characteristic of the triad is observable peripapillary atrophy or scarring. Two out of three of these findings are needed to make the diagnosis of presumed ocular histoplasmosis.
why does iodine deficiency cause goiter
lack of iodine => low circulating T3/T4 => ant pituitary secretes more TSH => overstimulation of thyroid => enlargement => goiter
Javal's rule
is used to predict the magnitude of refractive astigmatism based upon keratometry readings. The formula is: refractive astigmatism = (1.25 x the difference in keratometry readings) +/- 0.50D. If the astigmatism is with-the-rule, 0.50 D is subtracted; if the astigmatism is against-the-rule, 0.50 D is added to the results. If the astigmatism is oblique, 0.50 D is dropped from the equation.
what is Cetrimide agar used to culture
isolate gram neg bacteria
3 drugs that can cause myopia (NOT the only ones)
isoretinoin BC diuretics myopia from corneal swelling which steepens curve
The scotopic system displays a greater degree of temporal summation than the photopic system. According to Bloch's law, as long as the stimuli are delivered within the critical period, as the stimulus intensity increases what happens to the stimulus duration?
it decreases
AE of chloramphenicol? why is it so bad? useful for?
its very lipid soluble & easily crosses BAB -reversible bone marrow depression -aplastic anemia -gray baby syndrome (occurs if chloramphenicol is given within 2 weeks of birth) -optic neuropathy -teratogenesis -enterocolitis. useful for staph brain absecesses & certain types of meningitis
What is the most likely location, within the Circle of Willis, for aneurysms that result in pupil-involving Cranial Nerve 3 palsies?
junction of PCA and internal carotid
what are macula adherens & zonula adherens?
junctions that help weld cells together that are prone to being stretches zonula adherens form bands or collars that encircle cells
where are osteocytes found? role?
lacunae in the bone matrix -important in bone remodeling -release Ca from bones when body's Ca is depleted -derivatives of osteoblasts (bone formation)
what is LTK
laser thermal keratoplasty -for presbyopes w/ low hyper + cyl (like CK) -HOLMIUM laser skrinks peripheral collagen => steepening -temporary -will revert in 2-3 years
lateral conj lymphatics drain into? medial?
lateral = preauricular (aka parotid nodes) medial = submandibular
most common stromal dystrophy =
lattice (except type 3 which is AR)
path of CN 6
leaves junction of pons+medulla -> subarachnoid space, travels superior -> pierces dura, runs btwn dura + skull -> sharp anterior turn @ petrous tip of temporal bone to enter cav sinus -> runs along ICA -> enters orbit thru SoF -> LR muscle.
blood to aorta comes from which ventricle
left
ehlers-danlos pts are at risk for
lens subluxation (CT disorder)
What structures does the surface ectoderm give rise to?
lens, corneal & conjunctival epithelium, eyelid epithelium, lac gland, MGs, epithelial lining of nasolacrimal system
Nothnagel syndrome =
lesion of CN 3 fasicles + SUPERIOR cerebral peduncle (cerebellar????wrong?) ipsi third + ataxia
Benedikt syndrome =
lesion of CN 3 fasicles + red nucleus => ipsi third palsy + contralateral extrapyramidal signs (ex. hemitremor)
Weber syndrome =
lesion of CN 3 fasicles where they pass thru cerebral peduncle => ipsi third palsy + contralateral hemiparesis
blood-tinged debris on itchy inflamed lash margins =>
lice! phthriasis palpebrarum
what is an additive color mixture
light from 2 diff origins added together => combined effect has more light than either individual source Ex. TV projectors, spotlights with colored filters pointed @ same target
name 3 monocular cues to depth
linear perspective relative size motion parallax
simple epi is found where in body
lining body cavities, tubes & ducts -ABSORPTION, secretion, filtering or diffusion stratified = protection
which TF layer is secreted by blinking
lipid layer
Which agents stain dead cells, devitalized cells, and mucin?
lissamine + rose
malignant melanoma most commonly metastasizes to
liver
creatine is produced by
liver + kidneys energy source used 1* by muscle cells
Which of the following equations can be used to determine the optical density for a neutral density filter that transmits 20 percent of incident light? log / (1/0.2) log (1/0.8) log / (1/0.8) log (1/0.2)
log (1/0.2) OD=log(1/T)
describe mechanism of how accom influences IOP
longitudinal muscle contraction pulls on scleral spur which pulls on TM => decr resistance => lower IOP
what steroid should be used in a patient under age 10
loteprednol
loteprednol is an __-based steroid dex and pred are __-based steroids
loteprednol = ESTER dex + pred = ketone esters cause less IOP elevation
Older pts may say their vision clears with blinking - why?
many have bleph & blinking aids in stimulating release of lipid
most likely orbital bone to fracture
maxillary (floor)
What is Haab's striae
may be seen in primary congenital glaucoma and will appear as horizontal breaks in Descemet's membrane. Haab's striae may also present concentrically to the limbus.
The hairpin portion of the loop of Henle of a juxtamedullary nephron is located within which region of the kidney?
medulla
adrenal medulla secretes? cortex?
medulla = epi + NE cortex = cortisol + aldosterone
how does medulla regulate magnitude of normal breathing
medulla is surrounded by CSF if ppCO2 gets too high, CSF pH drops => medulla resp center increases breathing rate+depth
inheritance of megalocornea vs microcornea
mega: X-linked micro: AD or AR
main cause of a conj melanoma? main cause of squamous cell?
melanoma = 1* acquired melanosis squamous cell = CIN
CT is derived from
mesenchyme (a subtype of mesoderm)
AE of oral CAIs
metallic taste, paraesthesia, electrolyte imbalance, and aplastic anemia hypokalemia sulfa allergy
glands of moll, zeiss and MG are what type of glands (holocrine, apocrine, etc)
moll = apocrine (sweat) MG+Zeiss = holocrine (sebaceous)
pts with VKC and KCN tend to have what
more severe KCN greater tendency for HYDROPS + corneal neo
codeine is a prodrug of? how is it converted?
morphine converted to morphine by cytochrome p450 system within hepatocytes
How to insert lenses most common way?
most commonly used method is to insert the temporal aspect of the lens first followed by snapping the nasal edge into place from the front of the frame.
vogts is seen in what conditions
most seen in KCN can be in pellucid too
classic signs+sx of Pmonas infection
mucopurulent severe pain hypopyon ulcers (perforation within 48 hours!)
Giemsa stain of herpetic cells will show
multinucleared giant cells
3 findings that point to granulomatous uveitis
mutton fat KPs Koeppe nodules (pupil) Busacca nodules (anywhere on iris besides pupil)
what type of bacteria has no cell wall
mycoplasma (M. pneumoniae)
3 ocular AE of tricyclics (amitryptiline)
mydriasis cyclo increased IOP
what happens in diastolic CHF? occurs in what diseases
myocardium doesn't relax enough => reduced filling of ventricle occurs in sarcoidosis + hypertrophic cardiomyopathy
DM pts can get myopic or hyperopic shift, why
myopic = incr blood sugar hyperopic = downward fluctuations in sugar, treatment
Van Herrick: we place the lighthouse (nasal/temporal) to measure nasal angle? placing lighthouse at 70* will overestimate or underestimate angle?
nasal lighthouse > 60* = overestimate less than 60 = under
symp nerves to dilator follow course of which sensory nerve: A. facial B. nasociliary C. zygomatic
nasociliary (V1)
what condition classically results in reucrrent unilateral tearing
nasolacrimal duct obstruction
most common cause of dacryocystitis
nasolacrimal duct obstruction (so nasal origin, not ocular)
Metformin GI AE
nausea, vomiting, discomfort, diarrhea 3-5% of pts must d/c due to persistent diarrhea
AE of FL angio
nausea/vomiting within 30-60 sec (<5%) up to 1%: thrombophlebitis, localized tissue necrosis, nerve palsies, elevated temp severe/life threatening: anaphylaxis, laryngeal edema, bronchospasm, circulatory shock, MI.
a concave mirror has a + or - radius? + or - power? acts like what kind of lens?
negative radius (so POSITIVE power) F = -2n/r a concave mirror acts like a convex lens!
toxocara = what type of organism
nematode
which corneal condition causes LESS pain than expected on exam
neurotrophic (herpes, DM, stroke, CL overwear)
T/F: emmetropization means eye gaining 30 D of power in the years after birth
no - LOSING 30 D power!! (axial length lengthens from 16 mm to ~22, etc)
What are Berlin nodules?
nodules in the anterior chamber angle --best viewed with gonio
gluconeo = making glucose from what
non-carb sources such as lactate, glucogenic AAs or glycerol. -requires ATP+GTP -essentially reverse glycolysis, minus the 3 irreversible steps -FFAs cannot be used to make GL!
choriocapilaris is continuous with which layer of CB
none - choriocap ends with the retina
What color anomalous/dichromats can't do the duochrome test during refraction
none - they all can do it. it's completely independent of perception of color, it's just based on chromatic abbs
what is blood agar used to culture
nonselective medium, used to look at hemolytic activity
normal phenol red? normal anesthetized shirmer?
normal phenol = 10+ mm normal anesthetized shirmer 10+ mm
4 list examples of type 4 hypersensitivity
phlyctenules contact dermatitis PPD graft rejection
What is the approx critical duration for temporal summation in the photopic system? scotopic?
photopic: 10 ms scotopic: 100 ms
stiles-crawford effect =
photoreceptors are more sensitive to light rays from the center of the pupil than to light rays entering from periphery.
phenothiazine retinopathy is characterized by
pigmentary granularity + clumbing in mid-periphery & PP -chlorpromazine can also cause focal or diffuse atrophy of RPE + choriocap phenothiazines = chlorpromazine + thioridazine
roles of pars plana vs plicata
plana: zonules plicata: aqueous
what B cells secrete ABs
plasma cells (terminally differentiated B cells)
Pancoast tumor affects __G fibers can cause what Sx
preG miosis, ptosis, reverse ptosis, anhydrosis & dilation lag
neo in what location can cause an RD? what type of RD is this?
preretinal neo attaches to vitreous, which pulls retina off this is NON-RHEG
1/3 of optic nerve fibers leave & go where just prior to LGN
pretectal nuc (& then fibers leave pretectal and go to edinger)
purpose of valve of Hasner
prevents nasal cavity fluid from entering nasolacrimal system
how do we find image jump? base?
prism @ seg line using ADD only - dist Rx doesn't matter. P = cF P = (dist from OC to seg edge)(ADD) c = 5mm for a FT-28 c = 0 for an executive always base down (base is from OC of seg)
aniso worse in bright light which pupil is abnormal? possible causes?
probably the LARGER pupil. Adies CN 3 palsy Pharmacologically dilated pupil Iris sphincter damage
aniso worse in dim light which pupil is abnormal? possible causes?
probably the SMALLER pupil (doesn't dilate at the same rate as normal pupil)
role of chondroblasts
produce collagen matrix mature chondroblasts become chondrocytes + reside in cavities (lacunae) within cartilage matrix
3 primary brain vesicles
prosen (forebrain) mesen (midbrain) rhomben (hindbrain)
what is Unoprostone isopropyl (Rescula®)? Rxed for?
prostaglandin analog GL
ATP formation is driven by what force in OxPhor? describe oxphor
proton forced caused by a pH gradient OxPhor = synth of ATP via creation of pH gradient across mito memb -achieved via transfer of electrons thru redox rxns & protein complexes -transfer of e- from donors to acceptors releases energy, which is used to pump protons from mito matrix into intermembrane space (aka chemiosmosis) -pH difference causes protons to flow back into mito matrix thru pore in the enzyme ATP synthase -proton flow = energy for ATP synthase to phosphorylate ADP => ATP.
MOA of omeprazole
proton pump inhibitor
diff btwn true & pseudomembranes
pseudo - coagulum is deposited on epi surface, can be easily peeled off leaving epi intact true membranes infiltrate superficial layers of CONJ epi. trying to remove => bleeding, tearing of conj epi
Which type of epithelium lines the throat, nasal passages, sinuses and trachea?
pseudostratified (columnar) a modified simple - actually a single layer pseudostratified typically have cilia to sweep mucus or fluid across surface
most common cause of angioid streaks
pseudoxanthoma CT disorder that damages elastic core of Bruchs (but remember 50% of streaks are idio)
role of pons
regulation info btwn cerebellum & the integration centers of forebrain (cortex)
TH2 releases __ to promote switching what
releases IL-4 and 13 tells B cells to switch from producing intial IgM to IgE or IgG-4
TH1 releases __ to promote switching what
releases TGF-beta + IL-5 tells B cells to switch from producing intial IgM to IgA or IgG (1-3)
End-bulbs of Krause respond to
respond to temps below 20*C skin free nerve endings
raynauds =
restriction of blood flow to the extremities such as the fingers and toes, causing numbness or an excessively cool sensation, when exposed to decreased temperatures or stress
Roth's spots =
retinal hemes with whitish centers seen in bacterial endocarditis, leukemia, diabetes, and pernicious anemia.
what is RNA dependent DNA polymerase
reverse transcriptase
for LARS, right is counterclockwise or clockwise
right = CCW (left = clockwise)
vena cava empties into which atria
right atrium
Adrenal Cortex
secretes Cortisol - aldosterone (mineralcorticoid) also syn by adrenal cortex
Adrenal Medulla
secretes Epi and NE - reg blood circulation and metab of carbs when body is stressed
IgA is 1* found in? how common is it?
secretions its the 2nd most abundant AB in the body (IgG = most common)
what is Phenytoin (Dilantin) Rxed for? MOA? AE?
seizures blocks voltage Na channels in neurons => reduced repetitive firing nystag, miosis, diplopia, ophthalmoplegia
signs of thermal keratopathy causes sx when
severe confluent SPK interpalpebral, stains long sun exposure, welding Sx worse 6-12 hours after
Methotrexate is used to Tx
severe psoriasis severe active RA life-threatening cancer (has many AE, reserved for severe conditions where other Tx have failed)
How will the CS curve of an 80-year old be shifted compared to a young person
shifted slightly to the left (loss of high SF) WHY? #1 = pupil miosis (=> decr retinal illum) + aging neurons + scatter from NS
What is a nonsense mutation?
single nucleotide is sustituted for another, leading to a stop codon
what can accompany tilted discs
situs inversus fundus ectasia myopia ST VF defects that do not generally respect the midline.
what is Hay infusion agar used to culture
slime molds
Central retinal artery supplies
small portion of OPL, then everything anterior (INL, IPL, GC, NFL)
what is Coats white ring? what layer?
small white oval ring @ Bowmans AW previous FB
what are concretions? seen in?
small, chalky, whitish-yellow deposits typically found in the inferior tarsal and fornical conjunctiva. AW meibomian gland disease.
controllable risk factor fro thyroid EYE disease
smoking
CB is what muscle type
smooth (controlled by ANS)
diff btwn smooth & skeletal muscle nuclei
smooth = long spindle shaped cells, 1 nucleus per cell, ANS control skeletal = long multinucleated cells
Night myopia also occurs secondarily to mydriasis which causes an increase in what kind of aberration?
spherical aberration
what type of organism is coated in GAG
spirochete
left hemi =
spoken language math, music nonverbal abstract thinking
What is dimple veiling
staining pattern that is frequently observed in patients wearing gas-permeable contact lenses (it is rarely seen in soft lens wearers). This is believed to be the result of a poor fitting relationship between the contact lens and the cornea, leading to BUBBLES of carbon dioxide becoming trapped under the lens. These bubbles then cause indentations in the corneal epithelium, leaving tiny circular depressions that pool with sodium fluorescein when instilled (golf ball appearance). Dimple veiling will often resolve with a flatter lens, decreasing the overall diameter of the lens, or decreasing the optic zone diameter.
A lens that displays apical touch has been fit too flat and will likely also manifest excessive edge lift. Apical touch can cause distortion of the central cornea; also, in the event of extreme touch, corneal scarring may occur. Apical touch can be resolved either by....
steepening the base curve or by increasing the overall diameter of the optic zone.
what are the 2 binocular cues to depth
stereo convergence
arcus is where
stroma
sign of graft rejection in: Stroma? Endo?
stroma = Krachmer's spots Endo = Kodadoust line a type 4 hypersensitivity rxn
disciform keratitis is AW? affects what region
stromal HSV
IK = occurs in what 3 conditions
stromal inflam without 1* involvement of epi or endo #1 = congenital syph -stromal herp -TB
marfans is AW
sublux (ST) myopia strab RD cardiovasc abnormalities (aortic aneurysm, mitral prolapse)
in the optic tract, superior fibers are __ & inferior are __
superior = medial // parietal lobe inferior = lateral // temporal lobe
where do symps become post-G
superior cervical ganglion (near mandible)
actions of glucagon (4) target sites?
target tissues = liver + adipose released by PANCREAS when glucose low 1. stimulate glycogen breakdown 2. triggers gluconeo (fruct-1,6-bisphos) 3. inhibits glycogen synth + glycolysis by inhibiting glycogen synthase + phosphofruktokinase 4. increases lipase activity => more FFAs in blood to liver, muscle for breakdown/energy
prosencephalon becomes
telen + dien prosen is aka forebrain
blind spot is where on a VF printout
temporal VF
The muscle point that inserts onto a skeletal bone that does not move upon stimulation is known as what?
the origin (NOT the insertion, thats the other end?)
SWAP isolates
the small bistratified GCs (blue/yellow?) thought to be damaged earlier in GL, like magnos
what is done in conductive keratoplasty
thermal laser burns are placed in the mid-periphery of the cornea in an attempt to steepen the corneal curvature uses RADIOFREQUENCY energy (probe inserted in peripheral cornea
thrombi cause __ emboli cause __
thrombi = RVO emboli = RAO
The vital capacity of the lungs can be calculated by the summation of which 3 values?
tidal volume + expiratory reserve volume + inspiratory reserve volume. - Inspiratory reserve volume: the maximal volume of air that can be inhaled following a tidal inhalation - Tidal volume: the volume of air that is inhaled and exhaled during quiet breathing - Expiratory reserve volume: the maximal volume of air that can be exhaled at the end of a tidal exhalation
zylet =
tobradex + dexamethasone
Tx if EKC SEIs are visually debilitating
topical steroids
normal cholesterol
total <200 tri <150 LDL <130 HDL 40+
a tractional RD is rheg or non-rheg
tractional TEAR = rhegamatogenous traction on preretinal neo = non (vitreous just pulls retina off, there's no tear)
ideal polarizing sheet will absorb & transmit what
transmit 100% of light parallel to its transmission axis absorb 100% of light perpendicular to axis. transmittance of light that is incident at a certain angle from polarizing axis = Malus Law Tpol = cos^2(theta)
HSV reactivates from which ganglion
trigeminal (aka Gasserian)
describe a cavernous hemangioma. arises from? signs?
typically arise directly behind the eye (in circle of zinn) => progressive, unilateral proptosis -most common benign ORBITAL tumor in adults CAPILLARY hemangiomas = msot common benign orbital tumor in kids
optic nerve sheath gliomas
typically present with decreased visual acuity and are usually seen in patients who are in their first or second decade of life. Clinically, one may observe proptosis, a potential APD, optic disc pallor and/or swelling and hyperemia. The above patient does not have any of these signs.
ocular ischemic syndrome is typically uni or bilateral? sign? culprits?
typically unilateral midperipheral hemes Atherosclerosis + GCA
dont use FQs on what pts
under 18 MG (my
where is globe most likely to rupture with trauma
underneath a rectus muscle (sclera is thinnest where recti attach - 0.3 mm) 2 other locations = limbus or a previous surg site
role of IgD
unknown!
Children have asymmetric OKN until what age? how is it asymmetric?
until 3-5 years old (due to incomplete cortex development) Temporal-to-nasal NORMAL ("TONS of mvmt") Nasal to temporal abnormal a negative response to OKN is inconclusive (kid may just not be paying attention, or can't resolve stripes.)
systemic disorder with highest correlation with RP
ushers syndrome (ask about hearing loss)
Ehlers Danlos is caused by? inheritance? manifestations?
usually AD Hydoroxylysine deficiency Sublux, blue sclera, angioid streaks, KCN, megalocornea cardiovasc abnormalities like marfans (aortic aneurysm, mitral prolapse) + joint laxity
role of IgM
usually the first AB made in the immune response -LARGEST AB -can form pentamers with other IgM molecules in the secrete form
a maculopapular rash is typically seen in what type of infection
variety of viruses (ex. measles)
for the power factor formula how do we find d
vertex distance + 3 mm d = dist btwn back surface of lens & ENTRANCE pupil of eye (3mm behind cornea) (vertex 14 mm => d = 17 mm)
image for a plane mirror are: real/virtual? inverted/upright? reversed/not?
virtual reversed laterally inverted upright. same size as object appear as far from the mirror as the object is in front of the mirror.
total lung capacity is the sum of
vital capacity + residual volume Residual volume: the volume of air remaining in the lungs after a maximal exhalation vital capacity = tidal volume + insp reserve + exp reserve
Knapp's law =
when a correcting lens for an axial ametrope is placed at the primary focal point of the eye image size will be the same as an emmetrope (Ms = 1) axials get specs, refractives get CLs
Riddoch phenomenon =
when a stimulus is only observed when it is in motion, and cannot be detected by the observer when it is static. can be seen in occipital lobe lesions, ON damage or chiasm damage
Corneal edema or cataracts will reduce CSF of what spatial frequencies
will decrease CSF of ALL SFs (due to scatter/diffusing of light) use bailey-lovie or pelle-robson to assess contrast deficits
1 nanometer = _ meters
x10 ^-9
what tints enhance contrast
yellow or amber (amber for hunting, yellow for low light)
how does parinauds oculoglandular syndrome present
younger kid unilateral follicular cjvitis with ipsi PAN swelling.
which gland lubricates lashes
zeis
image jump for an executive bifocal =
zero, bc the seg OC is at the seg line
initial treatment and management of hyphema
•Complete medical and ocular history (including blood disorders) and medications used (aspirin, NSAIDs, warfarin, clopidogrel) •Complete ocular examination; it is most important to rule-out ruptured globe °Record level of hyphema, evaluate for corneal blood staining, measure IOP, perform DFE (without scleral depression), check for crystalline lens dislocation °Consider a gentle ultrasound biometry if fundus view or anterior segment view is poor, or if an intraocular foreign body is suspected °Avoid gonioscopy for at least 7 days •Consider a CT scan of the orbits and brain if indicated (suspected orbital fracture, intraocular foreign body, or loss of consciousness) •African-American and Mediterranean patients should be screened for sickle cell disease or trait (Sickledex) •Consider hospitalization for noncompliant patients, patients with blood disease, associated severe ocular or orbital injuries, those with significant IOP elevation and sickle cell, and some children (as described in the answer to the previous question) •Confine the patient to either bed rest with bathroom privileges or limited activity °The head of the bed should be elevated to allow blood to settle (~30 degrees) •Place a metal or clear plastic shield over the involved eye to be worn at all times °Do not patch because this would prevent recognition of sudden vision loss in the event of a secondary bleed •Treat with atropine 1% solution b.i.d. to t.i.d. (or scopolamine) °Immobilization of the pupil in the dilated state may prevent further hemorrhage and will aid in treating possible associated uveitis •Discontinue and/or do not allow any aspirin-containing products or NSAIDs °Only mild analgesics may be considered (acetaminophen) •If there is any suggestion of iritis, evidence of lens capsule rupture, or protein in the anterior chamber, topical steroids may be indicated (prednisolone acetate 1% four to eight times per day) •Treat any elevation in IOP as necessary °Start with beta-blocker °Avoid prostaglandin analogs and miotics due to the possibility of increased inflammation °Brimonidine may affect iris vasculature and should be used cautiously °Dorzolamide and brinzolamide may reduce aqueous pH and induce sickling in patients with sickle cell disease •Surgical intervention should be considered in the following conditions °Corneal stromal blood staining °Significant visual deterioration (as this can lead to amblyopia in younger patients) °Hyphema that does not decrease to <50% within 8 days °Certain conditions of significantly elevated intraocular pressure
What optical element provides the most refractive power
Cornea and tear film
UV absorption
Cornea does all of UV C while the lens does the majority of UV B and UV A
What alternations to the cornea commonly occur after several years of contact lens wear
Cornea epithelium thins Desensitized cornea
advancing nasal pterygium will increase WTR or ATR cyl
WTR (traction flattens 180*)
What area of the retina is most sensitive to detecting light flicker
Peripheral retina
Which one of the main proteins in the vitreous is comprised of a unique type of collagen? Albumin Creatine Vitrosin Hemoglobin
Vitrosin
Which type of vergence is NOT considered reflexive? Proximal Voluntary Fusional Accomodative Tonic
Voluntary
Compound Nevi
- nevus cells that extend from epidermis INTO DERMIS - raised tan/dark brown
strabismus surgery
- no surgery considered until >20 pd.
cover test
- stacking prism in SAME DIRECTION --> UNDER estimation of dev. - stacking prism in DIFFERENT direction --> NO effect - IN GENERAL: important to use accom. target, and wear habitual specs ; recommended to hold target slightly below patients eye level.
CL w/ ANISOmetropia
- using CL will minimize the image size difference bw the 2 eyes - with high rx (>4.00D) important to account for VD - patching important if pt still young (optimal age is 2-7) - must patch the GOOD eye to force patient to use bad eye - near activities recommended to stimulate accom. in the weaker eye - studies say part time patching is just as effective as full time, BUT better compliance with full time
Spitz Nevi
- variant of intradermal commonly presents as raised reddish lesion
If a +2.25 trial lens is added to a keratometer to extend the range in order to get a reading, how many diopters is needed to be added to the drum reading to get an accurate value
16 D
What age does the orbit reach its full size?
16 years
What is the ratio of artery:ciliary process?
1:1
Congenital cataracts can be caused by a viral infection of the mother with rubella virus (German measles) during development of the primary lens fibers. At which time period in embryonic development can infection cause congenital cataracts? 2nd trimester Conception 1st trimester 3rd trimester Post-delivery
1st trimester The developing lens is susceptible to rubella virus when the lens fibers are forming, which occurs around weeks 4-7 of gestation. Earlier infection will occur prior to lens fiber development, and the lens is resistant to later infection because the virus is unable to penetrate the lens capsule. The fetus is most susceptible to lenticular damage during the first trimester. Contraction of the rubella virus will cause the greatest amount of damage during this time period. Congenital cataracts are usually detectable at birth but may be seen later because the virus can persist in the lens.
prediabetic HbA1c range
5.7 - 6.4 (6.5 = DM) Tx target = below 7
CMV risk when CD4 count is less than
50
Arterial stenosis within which range is most likely to produce the sound of a carotid bruit upon auscultation
50-90% occluded
Rate of retinal ganglion cell axon loss per year?
5000 axons per year
The presence of foam at the canthus is thought to be pathognomonic for blepharitis. What is the direct etiology of the foam? Increased lysozymes react with free radicals to produce a froth-like material Bacterial lipases resulting from low-grade infection within the meibomian glands Mucin balls form from increased ocular surface shear forces exerted by the eyelids in dry eye Tear film debris such as sloughed epithelial cellular material that is increased in dry eye A detergent effect from altered meibomian gland lipids
A detergent effect from altered meibomian gland lipids The foam is considered to be caused by an alteration in the chemical composition of the meibomian lipids through a process termed saponification. Upon contact of these abnormal lipids with the calcium located in the tear film, a frothy tear film develops. Foam at the canthi is mentioned as a key diagnostic sign of MGD in most literature on the topic.
myogenic ptosis
A myogenic ptosis is one in which there is decreased levator function, which can be due to a myopathy of the actual levator muscle itself or an impairment in the transmission of nerve impulses at the neuromuscular junction. This type of ptosis can be congenital or acquired. Simple congenital ptosis is thought to be a result of a failure of neuronal migration and development during fetal growth. Acquired myogenic ptosis can occur in cases of localized or diffuse muscular dystrophy such as, myasthenia gravis, myotonic dystrophy, and chronic progressive external ophthalmoplegia. Classic signs of a myogenic ptosis are a weak or absent eyelid crease. In cases of congenital levator dysgenesis, there may be associated lagophthalmos in downgaze, and/or poor elevation in upgaze. In myasthenia gravis, the ptosis is typically variable and worsens with fatigue.
what type of drug is donepezil
Ach-esterase inhibitors (with echothiophate, edrophonium + pyridostigmine)
One of your tech-savvy low vision patients wishes to use a CCTV for reading. The CCTV operates on what principle of magnification? A. Relative size magnification B. Relative distance magnification C. Equivalent magnification D. Rated magnification
A. CCTVs work on the principle of relative size magnification (or projection). It operates by enlarging the text without lenses in front of the patient or the patient moving closer to the device. When the print is enlarged electronically in this matter, the image of the print subtends a larger area on the retina and thus a larger size. An example of relative distance magnification would be if you were holding a newspaper at 40 cm and you moved it closer to 20 cm. The print now appears 2 times as large relative to the 40 cm distance. Rated magnification is often used by manufacturers of some hand magnifiers and stand magnifiers using a 25 cm reference distance.
Decreased IOP
Alcohol, exercise, general anesthesia
Origin of the EOMs?
All have origins on the CTR except IO - comes from the maxillary bone
Which of the following congenital anomalies occurs if the optic vesicle fails to reach the surface ectoderm due to interference with closure of the neural tube?
Anophthalmos
Which of the following congenital anomalies occurs if the optic vesicle fails to reach the surface ectoderm due to interference with closure of the neural tube? Anophthalmos Keratolenticular stalk Iris Coloboma Microphthalmia Congenital glaucoma
Anophthalmos
An abnormally high positioned upper eyelid crease is indicative of
Aponeurotic ptosis
Convention flow of aqueous in the anterior chamber
Aqueous moves downward near the cornea where temperature is cooler and upward near the iris where the temperature is warmer
Dry eye and LASIK
At most risk are females over fifty, hyperopes, higher refractive errors, asians and look at the meds. Due to severing of corneal nerves
Once implantation of a fertilized egg occurs, the blastocyst will secrete a hormone that inhibits menstruation. What is the name of this hormone?
Human chorionic gonadotropin (HCG)
The visual acuity of a 77 year-old female patient with age-related macular degeneration is 2/16 in the right eye on the ETDRS chart. Why is this chart useful in monitoring the response to treatment with anti-vascular endothelial growth factor (VEGF)? A. Each line is 1.0 log units larger than the previous line B. Each line has 5 Sloan letters throughout the chart with equal spacing and is 1.26 times larger than the line below it; each line is .1 log units larger than the line below it when moving up the chart C. A three-line decrease represents a factor of a two time decrease in the size of the letters D. The Snellen construction of the chart enables the examiner to quickly note that a two-line increment represents a factor of a two time increase in the size of the letters
B. The ETDRS chart is a logarithmic eye chart modeled after the Bailey-Lovie chart. It is the primary standardized eye chart used in evaluating the visual acuity of low vision patients. The ETDRS charts are logMAR (log of the minimum angle of resolution) in design and are constructed with 10 Sloan sans serif letters. Each line is 1.26 times larger than the line below, and the construction of each line is such that the difficulty is theoretically equivalent on every line. The construction of the ETDRS chart is made to eliminate the inherent errors in the measurement of visual acuity found in the traditional non-standardized Snellen test charts. The Snellen test charts have variations in legibility of different letters as well as differences in the spacing between the lines of letters and between adjacent letters on single lines. The ETDRS logarithmic chart is constructed in such a way that each line of letters is 0.1 log units (about 1.26 times) larger than the previous line. This is a geometric progression.
Familial hypercholesteremia
Defective LDL receptors on cells so that the LDL cannot drop off the cholesterol to the cell and thus remains in the blood. HDL transports lipids to the liver and is good. VLDL is bad
What is Salus' sign? What grade of HTN retinopathy?
Deflection of the vein after an AV crossing Grade 2
Which of the following layers of the retina separates the retinal pigment epithelium from the underlying choriocapillaris? Outer limiting membrane Bruch's membrane Photoreceptor layer Outer plexiform layer Inner limiting membrane Inner plexiform layer
Bruch's membrane
A father brings in his two-year old son for evaluation at your office. The father remarks that his son was born with what appears as a small red birthmark on his forehead. He wishes to know if it requires treatment or warrants removal. Applying pressure over the area of interest causes blanching of the lesion, and the father reports that the birthmark appears darker when his son cries. What is your prognosis? A) Malignant and requires immediate biopsy B) A pre-cursor to a malignant condition and will continue to increase in size with time C) Benign and will likely regress by the time the child is 5 years of age D) Benign but is likely to be permanent and will darken will time
C) Benign and will likely regress by the time the child is 5 years of age [Capillary hemangioma]
Which of the following groups is NOT classified as association fibers which are used to support and brace the lenticular zonules? Orbiculociliary Ciliocapsular Circular Interciliary
Ciliocapsular - they support lens & accom. -arise from sides+valleys of ciliar processes + insert onto lens orbiculociliary arises from pars plana, connects to processes Interciliary fibers connect processes to each other Circulars run btwn zonules, connect them in a circular pattern like web
Healthy retina color
Clear, but looks orange red due to vasculature
What ion (other than iron) helps with anemia?
Copper
Bact assoc w/ diphtheria?
Corynebacterium
Which extraocular rectus muscle has its insertion site CLOSEST to the limbus? A.The lateral rectus B.The superior rectus C.The inferior rectus D.The medial rectus
D.The medial rectus Explanation The medial rectus inserts into the sclera roughly 5.3 mm from the limbus, followed by the inferior rectus, which inserts 6.8 mm from the limbus. The lateral rectus inserts 6.9 mm from the limbus, and the superior rectus has the furthest insertion point at 7.9 mm from the limbus. Remember MILS (Medial rectus, Inferior rectus, Lateral rectus, Superior rectus). If one draws a line connecting the insertion points of the muscles, an imaginary spiral is created called the spiral of Tillaux. SLIM: furthest to closest
4 conditions where oral steroids should be used with caution
DM HTN peptic ulcer psychosis steroids can cause hyperglycemia, water/NaCl retention => HTN, peptic ulcers, hypokalemia, exacerbation of psychoesis, osteoporosis + infection
Examples of DNA and RNA viruses?
DNA - herpes simplex, zoster, poxvirus, CMV, hepatitis B RNA - HIV, hepatitis A and C-E
An 81-year old female reports that her eye has been watering more frequently over the past month; you decide to administer the primary Jones dye test (Jones I). After 5 minutes, the application of a cotton-tipped applicator to the inferior turbinate reveals the presence of dye in the area. Taking this into consideration, what is the MOST likely cause of the patient's epiphora complaint? A. Complete nasolacrimal duct obstruction B. Punctal stenosis C. Dysfunction of the valve of Hasner D. Partial nasolacrimal duct obstruction E. Hypersecretion of tears
E. The primary Jones dye test can be utilized to determine the patency of the nasolacrimal system. 1-2 drops of fluorescein are instilled into the inferior fornix of the eyes while the patient is in an upright position and blinking her eyes normally. After a period of 5 to 10 minutes, a cotton-tipped applicator is used to swab the undersurface of the inferior turbinate on each side of the nasal passage. When the primary Jones dye test is positive (dye is recovered from the inferior turbinate of the nose), practitioners may conclude that the system is patent and that no significant blockage of the nasolacrimal drainage structure is likely. However, minor stenosis or physiologic dysfunctions cannot be completely ruled out. Patients who have a positive result on the Jones I test are more likely to experience symptoms of epiphora that are secondary to primary oversecretion of tears, rather than a dysfunction in lacrimal drainage (as in the above question). When the primary Jones dye test is negative, the probability of an obstruction or dysfunction in lacrimal drainage is much greater; however, this test alone is not sufficient to document this conclusion. The secondary Jones dye test is then necessary to determine the severity and location of the obstruction.
The vital capacity of the lungs can be calculated by the summation of which 3 of the following values? (Select 3) Total lung capacity Expiratory reserve volume Functional residual capacity Inspiratory reserve volume Residual volume Tidal volume
Expiratory reserve volume Inspiratory reserve volume Tidal volume
Your patient is having difficulty with learning to use a hand-held telescope to spot objects and signs at the grocery store, and while using during rides in the car. What is the BEST order of tasks to train him to help him achieve success with his telescope?
Eccentric viewing training with the preferred eye->spotting stationary objects while he remains stationary->spotting and tracking moving objects while he remains stationary->while he is moving, spotting stationary objects->while moving, spotting and tracking moving objects
what is FEV1 to FVC ratio? what is it in COPD pts?
FEV1=forced expiratory volume over 1 sec FVC = forced vital capacity -used to Dx obstrucive and/or restrictive lung disease -indicates amt of air that can be exhaled in 1 sec, in relation to the amt of total moveable air in lungs. normal = 80% in 1 sec, 90% in 3 sec (normals can exhale 80% of their vital capacity in 1 sec) obstructive disease => decr ratio (<70%) restrictive disease => FEV1 and FVC are equally reduced so ratio is ~normal; could even be elevated.
You suspect allergic conjunctivitis as the cause of your 22 year-old patient's symptoms of red, watery, itchy eyes. If you were to perform a conjunctival scraping, the presence of which of the following types of cells would confirm your diagnosis? Monocytes Eosinophils Neutrophils Basophils Lymphocytes
Eosinophils Allergic conjunctivitis is an ocular inflammatory response that is triggered by IgE-induced mast cell and basophil degranulation in response to an antigen. These cells, once degranulated, release histamines, cytokines, leukotrienes, prostaglandins, interleukins, chemokines and other mediators (early phase), which produce the classical symptoms of allergic conjunctivitis. In the later phase of the allergic response, infiltration of inflammatory cells such as eosinophils, neutrophils, and lymphocytes also occur, with eosinophils predominating. Therefore, if the conjunctival secretions were to be stained, one would likely observe numerous eosinophils present. Eosinophils are not typically present in the conjunctival scrapings of normal patients, so their presence is consistent with a diagnosis of allergic conjunctivitis.
What are B cells' primary targets
Extracellular toxins Pathogens circulating within the body tissues or fluids
For an emmetropic eye that is not accommodating, the chromatic interval within the eye would be positioned so that the anterior (green) and posterior (red) ends of the interval are equidistance from the retina
First and second principal points -- The first and second nodal points (N and N') of an optical system are unique conjugate points such that an incident ray directed at N yields a final ray emerging from N' that is undeviated and parallel to the initial ray. For any optical system in air, the first and second nodal points (N and N') correspond to the first and second principal points (P and P').
Fetal lens damage
First trimester
Congenital cataracts occur in what time period in embryonic development
First trimester (4-7 weeks of gestation)
First BC to use when fitting SCL?
Flat K + 0.8-1.0mm
function of calcitonin
GET RID OF CA -decreases blood Ca by inhibiting clasts -inhibits tubular resorp of Ca+phosphorus -> excretion
kochers sign =? occurs in?
GLOBE lag behind the upper lid mvmt in upgaze. thyroid eye disease. increased symps to lids => UL+LL retraction (muller + riolan)
Which of the following does NOT involve Acetyl CoA? -Beta oxidation -Fatty acid synthesis -Cholesterol formation -Gluconeogenesis
GNG
In what order does the neural retina develop?
Ganglion cells Horizontal cells Cones Amacrine cells Bipolar cells Rods Mueller cells
Caffeine is a central nervous system stimulant and is frequently used to maintain wakefulness. Which 4 of the following are common side effects of caffeine? (Select 4) Gastrointestinal irritation Itching of the scalp Nervousness Posterior subcapsular cataracts Osteoporosis Decreased blood pressure Dehydration
Gastrointestinal irritation Nervousness Osteoporosis Dehydration
Pretibial myxedema is an infiltrative dermopathy presenting on the anterior aspect of the lower legs that is a manifestation of which of the following systemic conditions? Systemic lupus erythematosus Grave's disease Multiple sclerosis Scleroderma Hypothyroidism
Grave's disease [waxy, discolored, raised plaques of non-pitting edema of the skin]
Abnormal palpebral fissure
Greater than 1 mm. Average is 11 or 9-12 mm
When is a difference in interpalpebral apertures considered abnormal?
Greater than 1mm
Group 1 contact lenses
Group 1 lenses possess low water content (less than 50%) and are composed of a non-ionic polymer.
Group 2 contact lenses
Group 2 lenses have high water content (greater than 50%) and are made from a non-ionic polymer.
Which of the following organisms can penetrate an INTACT cornea? Streptococcus aureus Salmonella enterica Haemophilus influenza Staphylococcus epidermis
Haemophilus influenza There is currently much debate in the literature regarding Pseudomonas because it was previously believed that Pseudomonas aeruginosa was capable of penetrating an intact cornea by secreting proteolytic enzymes that could break down the corneal barrier. However, current research suggests that this line of thinking no longer holds true. At present, it is believed that N. gonorrhoeae, Corynebacterium diphtheriae, Listeria species, and Haemophilus species are capable of infecting an intact cornea. Treatment commonly involves topical antibiotic ophthalmic drops. Streptococcus aureus, S. Epidermis, and Salmonella cannot penetrate an intact epithelium.
what test is done to confirm cat scratch fever
Hanger-Rose skin test
Lipemia retinalis
High cholesterol, over 1000. Possibility for development of pancreatitis
What does high v low corneal eccentricity indicate?
High eccentricity - flattens quicker in the periph Low eccentricity - flattens slower
Which of the following conditions may act as a protective factor against progression of diabetic retinopathy? High cholesterol High myopia Glaucoma Brown irides A high body mass index (BMI)
High myopia [More likely to have PVD, which would decrease risk of traction; therefore, risk of progression of DM retinopathy is decreased.]
Protective factor of diabetic ret
High myopia because they have probably already had a PVD and there is less risk of traction
Hudson-Stahli line
Horizontal iron deposition on inferior 1/3 of cornea associated with aging
Anisocoria greater in dim light
Horner's syndrome Argyll Robertson pupil Anterior uveitis (iritis) Miotic agent Long-standing Adie's pupil
Horners is a __ pupil thats worse in the __ Adies is a __ pupil thats worse in the __
Horners = miotic = dark Adies = dilated = light
Which form of visual acuity is most resistant to optical defocus
Hyperacuity (Vernier)
Which of the following forms of visual acuity is MOST resistant to optical defocus? Recognition acuity Hyperacuity (Vernier) Resolution acuity Stereoacuity
Hyperacuity (Vernier)
what are "allergic shiners"? cause?
Hyperpigmentation of the inferior periorbital skin from engorgement of superficial caps - downstream vasc congestion from inflam of nasal mucosa
Which Purkinje image moves forward with accommodation
III
anterior knee = what fibers
IN decussate anterior to chiasm bulge into contralateral ON, anterior to pituitary junctional scotoma = central fibers of one eye + inferior-nasal fibers (anterior knee) in other eye
Granit Harper law
If the size of a flickering stimulus increases, there is a greater chance of perceiving the flicker
Cataract classification
Immature is some opacification Mature is total opacification Hypermature is wrinkling due to leakage of water Morgagnian is liquefaction and inferior subluxation
A patient with a high AC/A ratio (8/1) displays esophoria at a 6 m distance. Based on the AC/A ratio, how would you expect the phoria to change as the target is brought closer to the patient? Remain unchanged Decrease in eso deviation Increase in eso deviation Increase in exo deviation
Increase in eso deviation If a patient possesses a high AC/A ratio, a 1D increase in accommodation will theoretically cause a greater increase in convergence. Regardless of the initial phoria, with decreasing viewing distance the phoria will become more eso (or less exo). The opposite holds true for a low AC/A ratio; as the target gets closer, the resultant phoria becomes more exo or less eso.
This patient has chosen the frame style shown in Image 1, but would like to order it in a larger size of 52 20 (originally 50 20). How will you need to change the segment height to compensate for the larger A measurement when you only have the smaller size in your office?
Increase segment height by 1mm. Usually, a given frame will use the same pattern for all eye sizes, so if the eye size is increased by 2 mm across the A dimension (as in this case), there will effectively be 1 mm of lens material added to the edge in every direction. Consequently, the distance from the geometric center of the lens to the lower bevel will be increased by 1 mm. At the same time, the distance from the desired segment height to the lower bevel also increases by 1 mm. Therefore, the segment height will need to be increased by 1 mm to maintain the same location of the upper line at the desired level. The opposite is true if the measurements are done on a frame that is larger than the patient desires.
What is the primary route of infection of patients diagnosed with hepatitis C
Intravenous drug use *risk of getting CRAO*
A 32-year old female is seen at your office complaining of a recent onset of blurred vision, only at a distance. A thorough case history reveals that she recently began taking a new medication which you correctly assume has induced myopia. Which of the following medications is MOST likely to be the culprit?
Isotretinoin, birth control pills, and diuretics, among many other drugs, can cause myopia in some patients. Myopia most likely results from corneal swelling, which steepens the curvature of the cornea. Drugs that cause swelling of the lens, accommodative spasm, or edema of the ciliary body will also result in myopia. A reduction in the dose of the medication or cessation of the offending drug will usually result in reversal of nearsightedness. Fish oil, Tylenol, and Tums have not been shown to have a correlation with transient myopia development.
"pseudo-KCN" topography can be caused by a CL that fits how
LA fit GPs often are Rxed with a flat or APICAL TOUCH fit relationship. physically flatten superior cornea => relative steepening inferior. to r/o KCN, stop lenses for a bit or refit with more central CL to slowly change topo back.
name the subdivisions of the nasociliary nerve (NFL/v1)
LINE long ciliary infratrochlear nasal posterior ethmoid
Axenfeld loops are smooth, dome-shaped, greyish-appearing nodules located under the bulbar conjunctiva that are a result of intrascleral looping of which of the following nerves?
Long posterior ciliary nerves
CN IV
Longest, only one that exits the branstem on the dorsal side and is contralateral
CL lag
Looking laterally
CL sag
Looking up
Mature v. hypermature v. Morgagnian
Mature - completely opaque crystalline lens Hypermature - opaque appearance to the lens + wrinkling and shrinking of the anterior capsule due to leakage of water out of the lens Morgagnian - hypermature + significant liquefaction such that the nucleus of the crystalline lens begins to sink inferiorly
What do vaccines produce to protect us?
Memory T cells
Which type of cell is involved in cell-mediated immune responses? Antibodies Effector B cells Memory T cells Memory B cells
Memory T cells
Treacher collins syndrome
Microphthalmos Cataracts Punctal atresia Antimongoloid slanting of palpebral apertures Lateral lower lid colobomas
what hormones do posterior pituitary produce
NONE! it releases ADH + oxytocin which the hypothalamus produces, transports via infundibular stem into pars nervosa of PP. stores hormones in Herring bodies (vesicles)
posterior pigmented epi of iris is continuous with
NPCE CB epi apexes face internally, while iris epi = apex to apex
posterior iris epi is continuous with _ and _
NPCE + retina
Where does pseudoexfoliative material come from?
NPCE of CB
HRCs (high-risk characteristics) for DMR
NVD > 1/4 DD Preretinal or vitreous heme with any NVD or NVE.
2 most abundant enzymes in NPCE =
Na/K ATPase + carbonic anhydrase
oubain blocks
Na/K pumps => decr aqueous production significantly
Which of the following medication classes, if used in conjunction with Viagra® (sildenafil citrate), will MOST likely lead to a potentially fatal drop in blood pressure? Nitrates Alpha-blockers Potassium-sparing diuretics Beta-blockers Calcium channel blockers Diuretics
Nitrates
Glycine
Only amino acid that is not chiral
Benzene ring amino acids
Phenylalanine, tyrosine and tryptophan. Histidine has a imidazole ring
absolute contraindication of using 10% topical phenylephrine?
Phenylephrine is a sympathomimetic, and as such it can affect the heart rate and blood pressure. Although rare, phenylephrine can cause tachycardia, arrhythmia, syncope, and an increase in blood pressure. A rapid increase in blood pressure has also been seen in people who suffer from idiopathic orthostatic hypotension. One must exercise caution when using phenylephrine. Be sure to monitor blood pressure in geriatric patients who suffer from cardiac disease. As an extra precaution, occlude the puncta for several minutes post-instillation to minimize systemic absorption. Phenylephrine may adversely interact with tricyclic antidepressants, monoamine oxidase inhibitors (Nardil and Parnate) as well as alpha adrenergic blockers like reserpine and guanethidine and therefore should not be used in patients who are taking these medications.
Perception of light that occurs when pressure is applied to the globe
Phosphene
Which enzyme is involved in the rate-limiting step of glycolysis?
Phosphofructokinase
Pilocarpine
Pilocarpine is a cholinergic agent that causes pupil constriction. In the event that a dilated pupil that responds poorly to light is encountered, one would suspect a third nerve palsy, pharmacologic block, or an Adie's tonic pupil. In order to distinguish between these three conditions, 0.125% pilocarpine should be administered, which would cause pupil constriction in a patient with an Adie's pupil but would not affect the pupil size in a cranial nerve (CN) III palsy or in a pupil that is dilated secondary to contact with a pharmaceutical agent. If constriction of the pupil in question does not occur with 0.125% pilocarpine, one drop of 1% pilocarpine should be administered to each eye. 1% pilocarpine will cause constriction of a pupil that is dilated due to a CN III palsy, while a dilated pupil caused by pharmacological block (as in the above patient) will remain unaffected.
In which of the following conditions are bandage contact lenses NOT typically utilized? Recurrent corneal erosion Bullous keratopathy Post-LASIK surgery Eyelid entropion Filamentary keratitis
Post-LASIK surgery
In which of the following conditions are bandage contact lenses NOT typically utilized? Eyelid entropion Recurrent corneal erosion Filamentary keratitis Bullous keratopathy Post-LASIK surgery
Post-LASIK surgery There are several indications for the use of therapeutic bandage contact lenses; however, when deciding to place a contact lens on an already compromised cornea, the risks and benefits should be carefully considered. Bandage contact lenses may be used to promote corneal epithelial healing in cases where an epithelial defect persists (abrasion or recurrent corneal erosion), as the lens acts to protect the epithelium from the rubbing action of the eyelids, allowing the hemidesmosomes to create a strong attachment to the basement membrane. In addition to promoting corneal healing, bandage contact lenses are also commonly utilized for pain relief in certain conditions such as bullous keratopathy, Thygeson's superficial keratitis, filamentary keratitis, and trichiasis. The bandage contact lens relieves pain by protecting exposed corneal nerves from the shearing forces of the eyelids during blinking or via mechanical protection of the cornea from inwardly turned eyelashes. Bandage contact lenses are also used post-surgically in all cases of photorefractive keratoplasty (PRK) to allow healing of the corneal epithelium that has undergone the surgical procedure. Contact lenses are not typically applied after LASIK surgery unless there has been a serious complication.
PPD cornea
Posterior polymorphous dystrophy appears as gray/white vesicles or rings within Descemet's membrane, often described as a "railroad track." The condition is generally bilateral, asymmetrical, and very slowly progressive. Most patients are asymptomatic and do not require treatment. This condition is generally observed at a much earlier age than Fuchs' dystrophy. There is a chance of iris abnormalities and the development of glaucoma with this condition.
Which of the following systemic conditions can cause a falsely low measurement of a patient's hemoglobin A1c level? Hyperbilirubinemia Chronic opioid use Iron deficient anemia Pregnancy Alcoholism
Pregnancy There are a few conditions that may cause a reading of hemoglobin A1c (HbA1c) to measure either falsely high or falsely low, therefore altering the reliability of the lab test. Conditions that falsely elevate A1c levels: -Iron deficiency anemia -Any process that slows erythropoiesis increases A1c by maintaining an older erythrocyte cohort in the blood plasma (e.g. aplastic anemia) -Alcoholism -Hyperbilirubinemia -Certain medications (high doses of salicylates, chronic opioid use) Conditions that falsely lower A1c levels: -Any process that shortens the lifespan of erythrocytes (e.g. hemolytic anemia, chronic kidney or liver disease) -Vitamins C and E (by inhibiting glycosylation of glucose to hemoglobin) -Pregnancy -Splenomegaly -Rheumatoid arthritis -Certain medications (antiretrovirals, ribavirin, and dapsone) -Hypertriglyceridemia In these cases, HbA1C levels may still be used to monitor blood sugar levels in patients with diabetes by comparison to previous readings in the same patient. However, goal values must be altered with respect to the underlying condition that is the cause of the unreliable result.
Medicamentosa
Pt reaction to a med or preservatives Sx - pain, FBS, burning, photophobia Ocular signs - conj injection, SPK, chemosis, ulceration, and scarring in very severe cases
Charles Bonnet syndrome
Pts with severe vision loss who experience hallucinatory images. Completely aware the objects that they are seeing are not real, and there is no history of mental disorder.
Decompression sickness is caused by
Rapid movement of *nitrogen* from the tissues into the bloodstream
32-year old male. CC: Fair amount of pain. He can barely open his right eye and reports that the pain began this morning when he first opened his eyes. MHx: Unremarkable. OHx: No contact lenses, mild corneal abrasion of the right eye from a tree branch that occurred over a month ago but had since healed. Biomicroscopy (after instillation of a topical anesthetic) reveals an epithelial defect 1.5 mm wide and 1.0 mm long that stains with sodium fluorescein. There is no anterior chamber reaction and no visible discharge. What is the MOST appropriate diagnosis?
Recurrent corneal erosion -- These types of corneal defects frequently occur in response to a corneal abrasion incurred by something organic (like a fingernail or a tree branch). The initial abrasion heals, but a short time afterwards the patient will experience another episode without any incidence of trauma. The second occurrence tends to transpire first thing in the morning as the eyelids stick to that unstable flap of tissue overnight and rip it off like a band-aid when the eyes open. Tx: Topical antibiotic (unpreserved is best) to ensure sterility (as the cornea is exposed) as well as a bandage contact lens to speed up the healing process if the area of erosion is large. Hyperosmotic drops or artificial tears (preservative-free of course) should be prescribed for roughly 6-8 weeks (sometimes longer) to ensure healing and to allow for proper formation of hemidesmosomes that will help to alleviate future episodes. Other Tx: Stromal micropuncture, debridement, phototherapeutic keratectomy (PTK), or oral tetracycline, which inhibits matrix metalloproteinases and allows for proper corneal healing.
Involuntary accommodation
Reflex (defocus,) proximal (increased awareness of target, scares you,) tonic and convergence (which is just induced when the eyes converge.)
What condition is characterized by the potential for glaucoma and a displaced pupil but no mental retardation or facial abnormalities?
Reiger's anomaly = GL + displaced pupil (iris strands, 60% GL risk) Reiger's SYNDROME adds MR and facial abnormalities.
Exit and entrance windows
Related to the field stops. Pupils are related to the aperture stop
What causes Rocky Mountain Spotted Fever?
Rickettsia (G-)
Where is the sclera weakest anteriorly?
Right behind the insertions of the recti muscles
When calculating the anticipated spherical over-refraction that the diagnostic contact lens will provide, you must take into consideration the tear lens, power of the ideal contact lens, and power of the actual diagnostic lens. How?
SAM FAP! Example: Desired Lens Rx: +2.75 Actual lens on eye Rx: +3.50 Expected over refraction: -0.75 tear lens = -0.37 because actual BC is 0.37 flatter But with FLATTER, add PLUS! -0.75 + 0.37 tear film = -0.37
body's first response to BV injury =
SM contraction (hemostasis) THEN: -platelet plug -then clot
bones of medial wall =
SMEL (medial = nose!)
blood supply to ONH is which 2 arteries
SPCA's and central retinal artery branches (minor contributor)
what med inhibits HMG-CoA reductase
Statins
A 63-year old female is seen at your office with a chief concern of blurry vision in the morning that takes about an hour to resolve before she can see clearly again. Biomicroscopy reveals endothelial guttata. You correctly diagnose her with moderate Fuch's dystrophy. Which ophthalmic drop would be of MOST benefit to her?
Sodium chloride is a topical hyperosmotic agent used to relieve stromal edema caused by endothelial decompensation. Topical steroids work well to decrease swelling caused by inflammation. In the above case, the corneal edema is not mitigated by an inflammatory response. Tobramycin and Vigamox would be of no benefit since there is no active infection, and prescribing either of these would only lead to corneal toxicity or increased pathogen resistance over time.
If apical clearance is observed, then the lens has been fit too _____.
Steeply. this will result in central pooling of sodium fluorescein and peripheral touch, which may then lead to sealing off of the cornea. Apical clearance can be remedied by flattening the base curve or by decreasing the overall lens diameter or optic zone.
Ptosis can be caused by dysfunction or damage to which of the following muscles? Superior tarsal muscle (muscle of Muller) Muscle of Horner Inferior rectus Pars ciliaris (Riolan's muscle)
Superior tarsal muscle (muscle of Muller) Ptosis is a condition in which the upper eyelid sags. It can be caused by dysfunction of either the superior palpebral levator or the superior tarsal muscle (muscle of Muller). Because the levator is the major muscle responsible for raising the upper eyelid, ptosis from levator damage is often more severe then ptosis from dysfunction of the muscle of Muller. The muscle of Horner (also known as the pars lacrimalis) is part of the palpebral portion of the orbicularis oculi. The fibers for the muscle of Horner come from the lacrimal crest and encircle the lacrimal canaliculi. This assists the flow of tears into the nasolacrimal drainage system when the orbicularis oculi contracts to close the eye. The muscle of Riolan (also known as the pars ciliaris) is another section of the palpebral portion of the orbicularis oculi; it lies near the lid margin to maintain the margins next to the globe. The orbicularis oculi is the major muscle responsible for closing the eyelids.
Medulla oblongata
Surrounded by CSF so can detect chemical changes like how an increase in CO2 will create a more acidic CSF. Thus the medulla controls breathing
Catecholamines
Sympathomimetics. Epinephrine, norepinephrine and dopamine. All come from tyrosine
Have to report to CDC
Syph, gonorrhea and chlamydia
Treponema pallidum
Syphilis
Which of the following infections must be reported to the CDC (Centers for Disease Control and Prevention)? Herpes Simplex Syphilis Epidemic keratoconjunctivitis (EKC) Acanthamoeba
Syphilis According to the CDC, all health care providers and laboratories must report new cases of syphilis to local and state health departments. Gonorrhea and Chlamydia trachomatis must also be reported along with many other serious types of infections that are easily spread and can produce long-term systemic effects.
What infections must be reported to CDC?
Syphilis Gonorrhea Chlamydia trachomatis Other infections that are easily spread, can produce long-term systemic effects
Interstitial keratitis can be seen in
Syphilis (#1) Herpetic leprosy lyme other viral diseases ALL pts with IK must undergo treponemal serological testing
Meds that cause crystalline maculopathies
Tamoxifen Canthaxanthin
What is the Gunn sign? What grade of HTN retinopathy?
Tapering of veins on either side of the AV crossing Grade 3
K readings
The axis given will be for the lowest K, the flatter K
What portion of the progressive lens should be used to verify the distance prescription when the lenses arrive from the lab? The center of the distance arc The major reference point (MRP) The center of the fitting cross The prism reference point (PRP)
The center of the distance arc When a progressive lens prescription is returned from the lab, it typically contains the removable markings that can be used for prescription verification and fitting purposes. Distance reference point (DRP) -Located at the center of the distance arc -Indicates the recommended position of the lens through which the distance prescription should be measured with a lensometer Fitting cross -Used to verify the fitting height -Should be centered on the patient's pupil -2 horizontal dashes to the right and left of the fitting cross help to determine whether the lens is level or tilted PRP (prism reference point) -Used to verify the prism power -This is the same as the MRP (major reference point) Near reference point (NRP) -Located at the center of the circle in the lower part of the lens -Used to verify the near add power
A 24-year old female patient presents at your office complaining of side effects that began when she started using Patanol to treat her ocular allergies. She reports complete compliance with her eye drop administration. Which of the following symptoms is MOST likely associated with olopatadine (Patanol) use?
Topical antihistamines and mast cell stabilizers such as Patanol (olopatadine) are commonly prescribed to relieve the symptoms associated with ocular allergies. They are a very effective class of medication due to their dual action mechanisms. Topical antihistamines that possess this dual action are olopatadine (Patanol), ketotifen fumarate (Zaditor), azelastine (Optivar), and epinastine (Elestat). The aforementioned drops serve to alleviate itching and redness by blocking H1 receptors as well as inhibiting mast cell and basophil degranulation. Side effects of topical antihistamine/mast cell stabilizers include stinging upon instillation, headaches, and adverse taste (don't forget to inform your patients about punctual occlusion!). Tachycardia, depression, gastrointestinal discomfort, and visual hallucinations have not been reported with Patanol use.
Elderly patients who suffer from nuclear sclerosis generally tend to display which type of color defect
Tritan defect
Your patient wants the lightest lenses available. Based on specific gravity alone, which of the following materials would be the best recommendation? CR-39 Polycarbonate High index plastic 1.60 Trivex
Trivex
When performing automated perimetry, when one fixates at a particular point, after about 20 seconds or so, a stimulus away from the fixation point will fade away and disappear. What is the name of this phenomenon? Troxler effect Stiles Crawford effect I Riddoch phenomenon Raynaud's phenomenon
Troxler effect
10-year old male. CC: Itchy eyes and severe photophobia. Hx: Eczema and hay fever. Biomicroscopy reveals bilateral cobblestone papillae of the superior eyelids, ropy discharge (worse in the morning), and mild superior corneal disruption that stains with sodium fluorescein. Given the above findings, what is your diagnosis?
Vernal keratoconjunctivitis (VKC) -- VKC is a condition of the young and presents like severe allergic conjunctivitis with an increased frequency in males. This type of allergy typically develops before age 14 and lasts for 4-10 years before the child outgrows it; VKC occurs predominantly in the spring and summer. Usually VKC is seen in patients who are prone to atopy; therefore they suffer from eczema, asthma, or hay fever. -- Tx includes mast cell stabilizers that should be started several weeks prior to re-occurring episodes, pulse steroid therapy, cool compresses, and sunglasses to help alleviate ensuing photophobia. -- Iritis, EKC, and bacterial conjunctivitis typically do not cause extreme itching and should not present with cobblestone papillae.
24-year old female. CC: eyes have been red for a few days. Biomicroscopy reveals bilateral diffuse superficial punctate keratitis (SPK) that stains with sodium fluorescein with no mucopurulent discharge. Based ONLY upon the corneal staining pattern, what is the MOST likely origin of her condition?
Viral -- Diffuse SPK likely signals either a viral origin or a toxic reaction to solution or topical ophthalmic drops. A bacterial etiology will cause staining of the inferior third of the cornea. Interpalpebral corneal staining is usually caused by lagophthalmos or environmental desiccation. A foreign body will either leave small punctate staining or tracks (especially if it is trapped under a contact lens).
Hubry 3 mirror lens posterior pole
Virtual upright image
Osteoarthritis
Wear-and-tear arthritis often referred to as degenerative joint disease. Low-grade inflammatory and metabolic component in the destruction of the cartilage, but OA is largely a mechanical disease
Hand neutralization
When hand neutralizing a lens, one must first determine if the lens is spherical or possesses astigmatism. While holding up the lens and looking through it at some type of cross hair grid or vertical line, rotate the lens and observe whether or not the line viewed through the glass appears to 'break' relative to the line that is not viewed through the lenses. If a break is observed, the lens has astigmatism. The location on the lens where the line appears to 'break' in the same direction of the rotation (with break) is the minus cylinder axis. The other principal meridian of the lens is located 90 degrees away and should exhibit 'against break' motion. Neutralize each meridian separately and place the answers on an optical cross. It is imperative to change the signs of the powers, as the true power of the unknown lens will be opposite those of the neutralizing lenses. The minus cylinder axis should be the meridian with the least minus power (or most plus power). The power of the lens can then be written in minus cylinder form. The axis can be determined by placing the lens against a protractor with the temporal and the nasal aspect of the frame aligned with the 180 and zero marks for the left eye, with the temples facing towards you (the 180 should always be located to the left for each eye and gradually decrease to zero while moving to the right). The location on the lens with the meridian that displayed 'with break' will be the minus cylinder axis
HLA-A29 =
birdshot chorioretinopathy
what causes horners reverse ptosis
lack of symps to muscle of riolan => LL sags
the anchor of the ciliary muscle is the
scleral spur
what is Malus Law
transmittance of light that is incident at a certain angle from polarizing axis = Malus Law Tpol = cos^2(theta) theta = perpendicular to absorption axis (if absorption axis isn't tilted, then theta=90 away from it)
Normal core temperature of the human body
37 degrees C or 98.6 degrees F
T lymphocytes cause which hypersensitivity
4
cholesterol's unique configuration?
4 joined cycloalkane rings
A patient is seen at your office complaining of distance blur with his glasses. With his current prescription of -1.25 D in place, you determine that his far point is 50 cm from the spectacle plane for his left eye. Given this information, which of the following is the MOST appropriate spectacle prescription to obtain a clear retinal image when an object is viewed at optical infinity (rounded to the nearest 0.25 D)? +0.75 D -3.25 D -2.00 D -0.75 D -1.25 D
-3.25 D With the current prescription in place, the patient's far point is 50 cm. The far point vergence at the spectacle plane necessary to obtain a clear image is the reciprocal of the far point, in meters. 1/0.50= 2.00 D. Therefore to achieve a clear retinal image for an object focused at optical infinity requires -3.25 D at the spectacle plane. Because the far point of 50 cm was determined with his current prescription in place, his prescription needs to be strengthened by the amount of the far point vergence required at the spectacle plane, which was -2.00 D in this case, and this value should be added to his prescription of -1.25 D.
10 mg/day of oral pred can lead to PSCs in how long
1 year but has been seen in as short as 2 months with as little as 5 mg/day
ONH reaches 95% of adult size at what age
1 year old but its not fully developed yet, esp. the lamina
Roughly how many ganglion cells are present in a human retina? 10 million 120 million 1 million 7 million
1 million
There exists some variation in the height of palpebral apertures between individuals; however, a difference greater than what degree seen between the two eyes of the same person is considered to be abnormal?
1 mm
spatial acuity using FCPL is expected to be what at: 1 month old? 1 year? when is it 20/20?
1 mo: 20/600-1,200 1 year: 20/50-60 reaches 20/20 around 3-4 years old.
Guideline for staying out of GPs before LASIK?
1 month per decade of RGP contact lens wear
How many photons to stimulate a rod? To generate a response?
1 photon per rod 10 photons (temporal/spatial summation) for a response
How much image jump will be created by a +2.00 D flat top 25 mm segment add with a carrier lens of +2.25 DS? 2.125 prism diopters 5.31 prism diopters 1.125 prism diopters 1 prism diopter 2.5 prism diopters
1 prism diopter Image jump is created by the vertical prismatic effect when looking through the reading addition of a bifocal lens. When the patient looks from the distance portion of their lenses into the reading area, the viewed image will appear to move or jump. The greater the distance between the reading add optical center and the bifocal line, the greater the image jump experienced by the patient. The total amount of image jump depends on the reading add and the distance between the optical center of the reading add and the segment line. The optical center of a flat top reading segment is located 5 mm below the segment line. Next apply the Prentice rule to solve this problem: prism diopters(pd) =d*F where d= the distance from the optical center in centimeters and F= the power of the add. Pd= 0.5(2.00) = 1 prism diopter.
How much image jump will be created by a +2.00 D flat top 25 mm segment add with a carrier lens of +2.25 DS? 1.125 prism diopters 2.5 prism diopters 5.31 prism diopters 2.125 prism diopters 1 prism diopter
1 prism diopter The optical center of a flat top reading segment is located 5 mm below the segment line. P = (0.5 cm) x (2.00D) = 1PD
how to pick RGP for alignment fit
1) 0.75 diopters flatter than the average keratometry reading btwn both eyes. Example: Average K = (44.62 + 43.12) / 2 = 43.87 Average K -0.75 D = 43.87 ? 0.75 = 43.12 OR 2) base curve is equal to the flat keratometry value Average K = (44.62 + 43.12) / 2 = 43.87 Average K -0.75 D = 43.87 ? 0.75 = 43.12
Which Purkinje images are formed by a combination of reflection and refraction?
1, 2, and 3 #1 is due to reflection only
What is the radius of curvature of the far point sphere (the axis about which the eye rotates when looking at the far point) for a pt who wears a -8.00 lens at 14 mm vertex, and CCR = 14 mm behind cornea. What is the CURVATURE of far point sphere?
1/8 = 12.5 cm 12.5 + 1.4 + 1.4 = 15.3 cm RADIUS -as eye rotates, it traces out a sphere w/ this radius. CURVATURE = 1/radius = 1/0.153 = 6.54 inverse-meters. also, curvature K = F/n. and radius of petzval surface is just 1/K, so you can compare it to petzval surface.
How to predict how much a toric lens has rotated based on the over-refraction?
10 degree rotation --> astigmatism ~1/3 of its original power in the over-refraction located at some oblique angle 15 deg rotation --> astig ~1/2 of its original power 30 deg rotation--> full amt of cyl power
Soft toric overrefraction
10 degrees = 1/3 of original cyl 15 degrees = 1/2 of original cyl 30 degrees = all of the original cyl Always at an oblique axis Think of clock dials, they are 30 degrees apart, so 30 degrees is a full, 15 degrees is half of a clock dial
How long does it takes cones to fully recover
10 minutes
Photostress test
10 seconds and under 60 seconds. Mono. Differentiates between macular and nerve problem, macula will have a longer recovery period
can a 10 D myope with a 500 um cornea have LASIK
10 x 15 um/D = 150 lost avg flap = 180 so will lose 330, have 170 left. need 250 remaining so NO
At a certain level of brightness, the rods become saturated and are unable to respond to an increase in stimulus intensity. How much rhodopsin must become bleached in order for rods to reach this level of saturation? 10% 100% 30% 80% 50%
10%
Rod saturation
10% of rhodopsin is bleached
Rod saturation occurs when
10% of the rhodopsin molecules have been bleached
defintiion of ICHEMIC CRVO
10+ DD of nonperfusion on FA -90% have 20/200 or worse
Size of cornea
10.6 mm vertically and 11.7 mm horizontally on the front surface and 11.7 mm both ways on the back surface
A chin fissure is a dominant trait. If a father who is homozygous-dominant for this trait and a mother who is homozygous-recessive for this trait mate, what are the chances that their first child will have a chin fissure? A.25% B.0% C.75% D.50% E.100%
100% Explanation Because the father is homozygous-dominant, it is indicated that he possesses a dominant gene pair for the chin fissure trait (FF). On the other hand, the mother is homozygous-recessive for this trait; therefore, phenotypically she would have a "normal chin" because she has an identical gene pair that does not code for a chin fissure (ff). Each child would receive an allele from each parent, but the pair of genes would not be identical (this is termed heterozygous (Ff)). However, because they would inherit a dominant form of the allele, this is the form of the gene that would influence the phenotype, resulting in the appearance of a chin fissure.
What percentage of each UV light is abs by cornea?
100% UVC 90% UVB 60% UVA
Corneal absorption
100% of UV C, 90% of UV B and 60% of UV A
A patient is using a stand magnifier of +16D with a +2.00 add. If the distance separating the two lenses is 25 cm what is the equivalent power of this combination? 10D 22D 18D 26D
10D Fe= F1+F2 -tF1F2 Fe = (16+2) - 0.25(16)(2) Fe= 18-8 = 10D
What is the mean horizontal and vertical diameter of the human cornea, respectively (when viewed ANTERIORLY)? 11.7mm, 10.6mm 11.5mm, 10.2mm 10.2mm, 11.5mm 10.6mm, 11.7mm
11.7mm, 10.6mm The human cornea has an elliptical configuration in which the mean horizontal diameter is 11.7mm and the mean vertical diameter is 10.6mm, when viewed anteriorly. Contrastingly, when viewed posteriorly, the cornea is actually circular, with mean horizontal and vertical diameters of 11.7mm. This discrepancy is due to the anterior extension of the opaque sclera superiorly and inferiorly.
bowmans thickness? comprised of?
12 um randomly arranged collagen fibrils (no cells) -smooth support for epi
tissue removal per diopter for LASIK
12-15 microns per diopter
Your 66 year-old female patient with a history of type 2 diabetes reports during case history that her last tested A1c level was about 6.0%. Which of the following MOST closely corresponds to her average blood sugar level in milligrams per deciliter (mg/dL)? 150 mg/dL 130 mg/dL 200 mg/dL 100 mg/dL 180 mg/dL 230 mg/dL
130 mg/dL 5.0% = 100 mg/dL 6.0% = 130 mg/dL 7.0% = 160 mg/dL etc.
Location of the physiological blind spot on the visual field testing
15 degrees temporal to fixation and slightly below the horizontal plane
NaFl angiography time to eye
15 sec
Corneal epithelial microcysts from low-Dk soft contact lens extended wear
15-50 micrometers in diameter Irregularly shaped Require about two months of extended contact lens wear to appear
What age does the globe reach its full size?
3 years
trace symps to the dilator muscle
1st-order neuron: Starts in the ipsilateral hypothalamus and synapses within the spinal cord at the Ciliospinal Center of Budge. 2nd-order neuron: Leaves spinal cord, travels over the apex of the lung, and synapses in the Superior Cervical Ganglion (near angle of mandible) 3rd-order neuron: exits the superior cervical ganglion, now as postganglionic fibers, unites with the internal carotid artery plexus (on top of the internal carotid artery), travels through the cavernous sinus (with CN VI near its side) and joins V1 to enter the orbit. Now it travels with the Nasociliary divison of V1 and ultimately innervates the dilator through the long ciliary nerve (branch of Nasociliary nerve).
where does tenons begin?
2 mm posterior to limbus (@ this spot, tenons fuses with backside of conj) more posterior (PP), tenons has pores that allow GC axons to enter eye
How long to be out of CLs for before LASIK?
2 weeks for SCL 2 weeks for EW SCLs 1 mo (at least) for GPs, with recommendation of 1 mo per decade of wear or until topo stabilizes
A tumor arises at the foramen ovale - what symptoms would you NOT expect? (Pick 2) 1. Difficulty with chewing 2. Loss of sensory innervation to cheek 3. Hearing loss on the contralateral side
2, 3 ovale = V3 = chewing
A patient with a visual acuity of 20/30 will likely display a high spatial frequency cut-off of how many cycles per degree (cpd)? 20 cpd 30 cpd 40 cpd 50 cpd
20 cpd 600/Snellen denom = cpd 600/30 = 20 cpd
greatest density of rods is __degrees from fovea
20*
leading cause of blindness ages: 20-74? over 50?
20-74: DM over 50: AMD
one-month old infant possesses roughly ___acuity
20/600 fpcl
mean lens power
21 D
triglycerides are comprised of
3 FA chains attached to glycerol backbone
Electrochemical Na/K pump
3 Na our for 2 K in
An Na/K pump pumps what in & what out?
3 Na+ OUT 2 K+ IN
Normal tear thickness
3 micrometers
tear thickness in a normal healthy young adult =
3 micrometers (some research said 40 micrometers recently but hasnt been confirmed)
Your patient wishes to see street signs and bus signs better with the aid of a hand-held telescope. The side of the telescope is marked 6x18. What is the diameter of the exit pupil? 18 mm 3 mm 0.33 mm 6 mm 10.8 mm
3 mm 18/6 = 3 mm
Two plane mirrors are joined at an angle such that the deviation of a reflected ray once at each surface of the mirrors is 280 degrees. What is the angle between the mirrors? 140 degrees 70 degrees 40 degrees 80 degrees
40 degrees deviation = 360 degrees - 2(theta)
typical young adult has high frequency cutoff around
40-60 cpd (MAR = 0.75)
Range of wavelengths of visible light?
400 to 700 nm (4-7 x 10^-9)
approx avg power of crystalline lens at birth
45 D then as axial length grows, lens loses 20 D by age 6. (emmetropization - 25 D by age 6.)
While performing the astigmatic clock dial, your patient reports that the 1-7 and 2-8 lines are equally blacker and clearer than all of the other lines. What would be the corresponding axis of astigmatism? 45 degrees 30 degrees 90 degrees 60 degrees
45 degrees In order to determine the corresponding axis of astigmatism utilizing the clock dial, one must multiply the smallest number of the clearest clock position by 30 degrees. In this instance, because the two lines are equally clear and black, the axis would lie in between them; therefore 1 x 30= 30 degrees. Each clock hour on the clock dial is separated by 30 degrees. Midway between the 1 o'clock and 2 o'clock position is 30 degrees divided by 2 thus, 30/2= 15 degrees. We must now add 15 degrees to our previous number of 30 degrees because the astigmatism axis lies in between the 1 and 2 o'clock positions. This would give us a total of 45 degrees.
Protanope neutral point + colors perceived above and below it
492 Above - perceived as yellow Below - perceived as blue
Young strab child. Visuoscopy. Fixate OD. Occlude OS. Foveal reflex 3 hash marks left of center circle of target. Which type of fixation?
4^ Nasal eccentric fixation -- Visuoscopy is an excellent technique to evaluate for eccentric fixation. This is performed by using the cross-hair target of your direct ophthalmoscope and projecting it onto the macula of the unoccluded eye. The patient is asked to fixate on the center of the target. No eccentric fixation is present if the foveal reflex aligns with the center of the cross-hairs. From the center of the circle on the visuoscopy target to the edge of the circle is one prism diopter, and then each hash mark away from the center circle is an additional prism diopter.
You have a telescope upon which the markings are unreadable. You wish to determine the magnification of the telescope. The objective lens measures 16 mm and the ocular lens measures 6 mm. You are able to accurately measure the exit pupil to be 4 mm. What is the magnification of the telescope? 2.6x magnification 1.5x magnification 5x magnification 4x magnification
4x magnification telescope mag = obj lens diam / exit pupil diam
how many layers in bruchs
5
dist from OC of seg to seg edge for a FT 28 =
5 mm
What is the equivalent of a reduced Snellen 20/30 optotype in point notation (assuming a distance of 40 cm)? 5 point 6 point 4 point 9 point
5 point [Divide Snellen denominator by 6]
What is the vergence demand using a Variable Tranaglyph when the separation is measured as 4 cm at a distance of 80 cm when training divergence? 20 prism diopters base-out 20 prism diopters base-in 5 prism diopters base-in 5 prism diopters base-out
5 prism diopters base-in The equation to calculate vergence demand is: demand = target separation in centimeters/training distance in meters demand = 4 cm/0.80 m demand = 5 prism diopters Because divergence is being trained in the above patient, the demand will be base-in. If convergence was being trained, the demand would be base-out.
What %age of general pop are steroid responders? Of POAG pts? Of those who have POAG parents?
5% of general pop 90% of POAG pts 25% of offspring
Normal human aging results in the gradual loss of retinal ganglion cells at an approximate rate of
5,000 axons per year of life
Ganglion cell loss with age
5,000 per year. Lose more in the periphery than in the macula.
endo @ birth =
5000 cells/mm2 loss of clarity occurs at 500 cells/mm2
If using the clock dial to determine the axis of astigmatism, what is the numerical value of the degree to which the axis of the principal meridians can be refined? 7.5 degrees 15 degrees 5 degrees 30 degrees
7.5 degrees
Fan chart can refine axis up to what degree
7.5*
radius of curvature of central cornea, anterior vs posterior?
7.8 mm anterior 6.5 mm postieriorly (so steeper posteriorly)
An object is 2 m from a 7^BD prism. How much is object displaced when viewed thru prism, & which direction?
7^ means displacement is 7 cm for an object 1 m away, so 2 m away means 14 cm deviation. BD means it's displaced up (apex). 14 cm up.
If a +1.25 trial lens is added to a keratometer to extend the range in order to get a reading, how many diopters is needed to be added to the drum reading to get an accurate value
8-9 D
Your patient would likely be able to read the power point slides during office meetings using a bioptic. The font size is approximately 20/50. What would be the MOST appropriate power of a bioptic telescope to meet this goal, and which eye would you mount the telescope over?
8x right eye angled up. To calculate the needed magnification, take the denominator of the 20 foot equivalent of the visual acuity of the better-seeing eye and divide it by the denominator of the goal optotype size. 400/50=8x. The right eye possesses better acuity and should be fitted with the bioptic. If visual acuity between the eyes is symmetrical or if there is a strong dominance displayed for a preferred eye, you may reconsider for which eye to prescribe a telescope.
Avg life cycle of PR disc?
9-13 days
Life time of photoreceptor discs
9-13 days
A patient with narrow angles at risk for angle-closure is accidently dilated with 1% tropicamide by a staff member at your office. After the instillation of drops, what time period is the patient MOST likely to experience angle-closure? 120 minutes 30 minutes 15 minutes 90 minutes
90 minutes
when does 2* vitreous begin to develop in gestation
9th week
60 watt bulb is moved from 3 feet to 1 foot from page. how much is page illumination increased
9x the original brightness
ESR for women
=(age + 10)/2
ESR for males
=age/2
Which of the following correctly lists the layers of the retina beginning with the retinal pigment epithelium and moving anteriorly? A. Retinal pigment epithelium, photoreceptor layer, external limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, internal limiting membrane B. Retinal pigment epithelium, external limiting membrane, outer nuclear layer, photoreceptor layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, nerve fiber layer, ganglion cell layer, internal limiting membrane C. Retinal pigment epithelium, photoreceptor layer, outer nuclear layer, external limiting membrane, outer plexiform layer, inner plexiform layer, inner nuclear layer, ganglion cell layer, nerve fiber layer, internal limiting membrane D. Retinal pigment epithelium, outer nuclear layer, external limiting membrane, photoreceptor layer, outer plexiform layer, inner plexiform layer, inner nuclear layer, nerve fiber layer, ganglion cell layer, internal limiting membrane
A In order: 1) The retinal pigment epithelium is a single layer of pigmented cells that functions to form part of the blood-retinal barrier, phagocytose fragments from shedding of photoreceptor discs, and metabolize and store vitamin A which is used in forming photopigment 2) The photoreceptor cell layer contains the outer and inner segments of rods and cones 3) The external limiting membrane consists of intercellular junctions of photoreceptor cells 4) The outer nuclear layer contains the cell bodies and nuclei of the rods and cones 5) The outer plexiform (synaptic) layer is made up of the fibers of rods and cones and synapses between photoreceptor cells and cells from the inner nuclear layer 6) The inner nuclear layer contains cell bodies of several types of neurons and Muller cells. 7) The inner plexiform (synaptic) layer contains the synapses of bipolar cell axons and gangion cell dendrites 8) The ganglion cell layer contains amacrine cells, Muller cell bodies, and astroglial cells 9) The nerve fiber layer contains the ganglion cell axons 10) The internal limiting membrane forms the innermost boundary and is composed of footplates of Muller cells Ref: Remington, LA. Clinical Anatomy of the Visual System, 1998 p 59-65
Chronic blepharitis, if left untreated, can cause which of the following structural changes to the anterior ocular segment? A. Madarosis B. Distichiasis C. Hypertelorism D. Tristichiasis
A. Blepharitis is a condition caused by pathogens, usually of Staphylococcus origin, that colonize along the eyelid margins. The bacteria produce exotoxins which take the form of flakes and are generally seen along the base of the eyelashes. Unfortunately, this condition is chronic but will wax and wane in its presentation. Long-term complications include madarosis (missing lashes), trichiasis, neovascularization of the eyelid margin, keratitis, erythema, phlyctenule formation and infiltrates. Patients may complain of dry, irritated eyes, stinging, pain, itching, frequent eye infections, foreign body sensation, and decreased acuity (if there is corneal involvement). Treatment includes eye lid scrubs, antibiotic ointments and sometimes transient topical steroid use to decrease lid inflammation (usually used in conjunction with a topical antibiotic). Occasionally oral antibiotics are prescribed, especially in the event of poor compliance. Distichiasis is a rare congenital phenomenon marked by an absence of meibomian glands. In the place of the meibomian glands is an extra row of eyelashes. Hypertelorism is a term used to describe the incidence in which the orbits are located quite far apart. This generally occurs along with other congenital cranium anomalies. Tristichiasis is a very rare occurrence in which a person possesses three rows of eyelashes.
Ptosis can be caused by dysfunction or damage to which of the following muscles: A: Superior tarsal muscle (muscle of Muller) B: Muscle of Horner C: Inferior rectus D: Pars ciliaris (Riolan's muscle)
A. It can be caused by dysfunction of either the superior palpebral levator or the superior tarsal muscle (muscle of Muller). Because the levator is the major muscle responsible for raising the upper eyelid, ptosis from levator damage is often more severe then ptosis from dysfunction of the muscle of Muller. The muscle of Horner (also known as the pars lacrimalis) is part of the palpebral portion of the orbicularis oculi. The fibers for the muscle of Horner come from the lacrimal crest and encircle the lacrimal canaliculi. This assists the flow of tears into the nasolacrimal drainage system when the orbicularis oculi contracts to close the eye. The muscle of Riolan (also known as the pars ciliaris) is another section of the palpebral portion of the orbicularis oculi; it lies near the lid margin to maintain the margins next to the globe. The orbicularis oculi is the major muscle responsible for closing the eyelids.
A 24-year old female wears soft contact lenses with a Dk/t of 175 and admits to sleeping in her lenses. She is very satisfied with both the comfort and the vision of her lenses. Biomicroscopy reveals mucin balls under her lenses bilaterally that leave impressions in her central corneas upon removal of her lenses. Which of the following actions would BEST help to eliminate the formation of mucin balls? A. Maintaining the same lens material but changing to a steeper base curve B. Instructing the patient to increase her blinking frequency C. Changing her multi-purpose solution D. Altering the power of the contact lens but maintaining the same lens material
A. Mucin balls appear as small, white, pearl-like debris that occur behind the posterior surface of contact lenses. They generally occur with silicone hydrogel lenses that are fit too flat and are used for extended wear purposes. Mucin balls do not actually pose a threat to vision and do not generally compromise the integrity of the cornea. However, if they are severe enough, there are several options available to clinicians to combat their formation. An easy way to decrease generation of mucin balls is to steepen the base curve of the lens. Alternatively, one can decrease the amount of extended wear or add re-wetting drops to the patient's contact lens regimen. Upon removal, mucin balls will cause pooling of sodium fluorescein but will not cause staining of the cornea.
Tear volume in a normal, healthy, young adult measures approximately between which of the following values? A: 6.0-8.0 microliters B: 2.0-5.0 microliters C: 9.0-12.0 microliters D: 17.0-20.0 microliters E: 13.0-16.0 microliters
A. Tear volume has been measured by several methods to be approximately 6-7 microliters in normal individuals, with lesser values occurring in conditions of aqueous tear deficiency. This has implications for drug delivery, since the normal ophthalmic drop volume varies between 25 and 50 microliters, effectively overwhelming the native tear value upon instillation.
Which two layers of the iris are derived from mesoderm? A. The anterior limiting layer and the stroma B. The stroma and the anterior epithelium C. The epithelium and the posterior pigmented epithelium D. The stroma and the posterior pigmented epithelium E. The posterior pigmented epithelium and the anterior limiting layer
A. The iris can be classified into four layers. The most external is the anterior limiting layer, followed by the stroma, the anterior epithelium and the posterior pigmented epithelium which is the most internal layer. The first two layers are derived from mesoderm. The anterior limiting layer contains numerous melanocytes and fibroblasts. Interestingly, this layer is not present over Fuch's crypts. The anterior limiting layer is not uniform and varies in density across the entirety of the iris. There is some debate as to whether or not this layer exists and therefore can be simply classified as stroma. The stroma is the thickest layer of the iris and is comprised mostly of collagen. The stroma houses many structures including; blood vessels, pigmented cells, nerves and the sphincter muscle. The epithelial layers are derived from neuroectoderm.
A cornea that displays toricity is said to have with-the-rule astigmatism if it possesses which of the following keratometry readings? A. The vertical meridian is steeper than the other principal meridian B. The vertical meridian is flatter than the other principal meridian C. The horizontal meridian is steeper than the other principal meridian D. The horizontal meridian has a shorter radius of curvature
A. With-the-rule astigmatism occurs when the vertical meridian is steeper than the other principal meridian; that is, the horizontal meridian is flatter and corresponds with the axis of the astigmatism. In this case, the vertical meridian would have a shorter radius of curvature indicating that it possesses a greater dioptric power than the horizontal meridian. If the steeper meridian lies between 60 and 120 degrees, the cornea is said to have with-the-rule astigmatism. If the steeper meridian lies between 150 and 30 degrees, the cornea displays against-the-rule astigmatism. Anything outside of these meridians is considered oblique astigmatism.
A 2.5x Galilean telescope has a -25D ocular lens. When focused for infinity, what is the length of the telescope? A. 6 cm B. 5 cm C. 10 cm D. 4 cm E. 14 cm
A. M = -Doc/Dobj where Doc=power ocular; Dobj= power objective; t= separation of lenses 2.5= - (-)25/Dobj Dobj= 10D t= f'obj + f'oc f'obj=1/10D = 0.10 m f'oc = 1/-25D = 0.04 m t=0.10 + -0.04 = 0.06 m or 6 cm 10 cm - incorrect- would come up with this answer if only took in account the focal length of the objective lens. 4 cm - incorrect- would come up with this answer if only took in account the focal length of the ocular lens. 14 cm - incorrect - would come up with this answer if thought equation was t= f'obj + f'oc
When performing a unilateral cover test on your patient, you note the following: upon covering the right eye, the left eye moves in 1/10 times. Upon covering the left eye, the right eye moves in 4/10 times. The alternating cover test measures 25 prism diopters base-in. What is your diagnosis based on these findings? A. 25 prism diopter intermittent alternating exotropia; left eye preferred B. 25 prism diopter intermittent alternating esotropia; left eye preferred C. 25 prism diopter intermittent alternating exotropia; right eye preferred D. 25 prism diopter intermittent alternating esotropia; right eye preferred
A. 25 prism diopter intermittent alternating exotropia; left eye preferred Explanation The unilateral cover test will tell you the eye (or eyes) affected, the direction, and the frequency of the ocular deviation. In this case, the eyes lose fixation 5/10 times, which shows that the frequency is intermittent (it would be constant if at least 1 eye moved 10/10 times). Since each eye moves at least once when the other is covered, the deviation is considered to be alternating. The uncovered eye is noted to move "in" on unilateral cover test, meaning that the deviation is an exotropia (if the eye moves "out" it is an esotropia). Since the right eye loses fixation more than the left eye (4/10 vs. 1/10), the left eye is considered to be the preferred eye. Also, the alternating cover test will tell you the full amount of the deviation, which is 25 prism diopters in this case.
A 2.5x Galilean telescope has a -25D ocular lens. When focused for infinity, what is the length of the telescope? A.6 cm B.5 cm C.10 cm D.4 cm E.14 cm
A. 6 cm Explanation M = -Doc/Dobj where Doc=power ocular; Dobj= power objective; t= separation of lenses 2.5= - (-)25/Dobj Dobj= 10D t= f'obj + f'oc f'obj=1/10D = 0.10 m f'oc = 1/-25D = 0.04 m t=0.10 + -0.04 = 0.06 m or 6 cm 10 cm - incorrect- would come up with this answer if only took in account the focal length of the objective lens. 4 cm - incorrect- would come up with this answer if only took in account the focal length of the ocular lens. 14 cm - incorrect - would come up with this answer if thought equation was t= f'obj + f'oc
A patient is concerned with an acute reduction of the acuity in the right eye. You correctly diagnose central serous retinopathy, and confirm your diagnosis with an optical coherence tomography (OCT). What is the standard treatment protocol? A.Monitor monthly for resolution B.Refer for laser treatment of the retina C.Treat the patient with prism as they are likely to develop diplopia D.Refer for intravitreal steroid injection E.Refer for cryotherapy of the retina
A.Monitor monthly for resolution Explanation CSR is more commonly seen in middle-aged males under high-stress, who are very anxious, or with type A personalities. This condition causes fluid to leak from the choriocapillaries into the subretinal area, causing a serous detachment of the neurosensory retina. There is an associated loss of the foveal reflex, a hyperopic shift, a potential relative scotoma, and metamorphopsia. Flourescein angiography will reveal hyperfluorescence that appears like a smoke-stack. Evaluation of the posterior pole will typically display a blister-like elevation of the neurosensory retina. The patient is monitored monthly and intervention is rarely required, as most cases of CSR will resolve within roughly 6 months.
One of your tech-savvy low vision patients wishes to use a CCTV for reading. The CCTV operates on what principle of magnification? A.Relative size magnification B.Relative distance magnification C.Equivalent magnification D.Rated magnification
A.Relative size magnification Explanation CCTVs work on the principle of relative size magnification (or projection). It operates by enlarging the text without lenses in front of the patient or the patient moving closer to the device. When the print is enlarged electronically in this matter, the image of the print subtends a larger area on the retina and thus a larger size. An example of relative distance magnification would be if you were holding a newspaper at 40 cm and you moved it closer to 20 cm. The print now appears 2 times as large relative to the 40 cm distance. Rated magnification is often used by manufacturers of some hand magnifiers and stand magnifiers using a 25 cm reference distance.
What is the name of the pigmented line that represents the leading edge of a pterygium? A.Stocker's line B.Fleischer's ring C.Krukenberg's line D.Ferry's line E.Hudson-Stahli line F.Coat's white ring
A.Stocker's line Explanation - Stocker's line is a deposition of iron in the corneal epithelium that is located at the leading edge of a pterygium - A Hudson-Stahli line is an iron line that is commonly observed at the junction of the middle and lower third of the cornea (where lid closure occurs upon blinking) - Ferry's line is found in front of a filtering bleb - Coat's white ring is a small, white, oval ring at the level of Bowman's membrane that is associated with a previous corneal foreign body - A Fleischer ring is an iron pigment that encircles the base of a cone in keratoconus - A Krukenberg spindle is a deposition of pigment on the corneal endothelium that is associated with pigment dispersion syndrome
Which of the following ocular signs is virtually pathognomonic for trachoma caused by chlamydia? A.Superior tarsal follicles B.Lymphadenopathy C.Inferior tarsal papillae D.Tranta's dots
A.Superior tarsal follicles Explanation Chlamydia causes two forms of conjunctivitis, trachoma and inclusion. Trachoma is more common in lesser-developed countries and can cause blindness if not treated appropriately. Trachoma presents in several stages, initially starting with mucopurulent discharge, lymphadenopathy, red eye, small superior tarsal follicles, and mild superior pannus. As the condition evolves, the formation of limbal follicles occurs and will eventually scar causing Hebert's pits, which are characteristic of this infection. This condition, if left untreated, ultimately progresses to horrible scarring of the eyelid (Arlt's line) and cornea, causing extremely poor visual acuity. Diagnosis is made with the observation of two or more of the following: follicles on the upper tarsus, pannus (particularly superiorly), limbal follicles or Herbert's pits and typical conjunctival scarring of the upper lid. Treatment includes oral doxycycline, tetracycline, or erythromycin along with topical tetracycline or erythromycin ointment. Azithromycin is also a good choice because it is given as 1000 mg PO which delivers exceptional compliance; however, this is not to be prescribed to those with liver disease or to young adults under the age of 16. Inclusion conjunctivitis is linked to venereal disease and can present either unilaterally or bilaterally (which is more common) as follicles on the upper and lower tarsal plates (lower follicles will be larger and more prominent), lymphadenopathy, possible mucopurulent discharge, lid edema, micropannus, superior corneal sub-epithelial infiltrates, superficial punctate keratitis, and scarring of the upper eyelid (sometimes called Arlt's line or "basketweave" because of its appearance). This type of conjunctivitis is less severe than trachoma. Treatment is similar to that of trachoma. Follicles are related to cellular immunity which serves to protect against viruses. Many types of viral infections can cause inferior palpebral follicles, such as EKC, Herpes simplex and molluscum contagiosum. Superior tarsal follicles are highly suggestive of a chlamydial infection. A superior papillary response is generally associated with an allergic response. Inferior tarsal papillae are frequently seen in bacterial infections and allergic responses as papillae act as the release sites for both eosinophils (associated with allergies) and polymorphonuclear leukocytes which destroy bacteria.
Ptosis can be caused by dysfunction or damage to which of the following muscles? A.Superior tarsal muscle (muscle of Muller) B.Muscle of Horner C.Inferior rectus D.Pars ciliaris (Riolan's muscle)
A.Superior tarsal muscle (muscle of Muller) Explanation Ptosis is a condition in which the upper eyelid sags. It can be caused by dysfunction of either the superior palpebral levator or the superior tarsal muscle (muscle of Muller). Because the levator is the major muscle responsible for raising the upper eyelid, ptosis from levator damage is often more severe then ptosis from dysfunction of the muscle of Muller. The muscle of Horner (also known as the pars lacrimalis) is part of the palpebral portion of the orbicularis oculi. The fibers for the muscle of Horner come from the lacrimal crest and encircle the lacrimal canaliculi. This assists the flow of tears into the nasolacrimal drainage system when the orbicularis oculi contracts to close the eye. The muscle of Riolan (also known as the pars ciliaris) is another section of the palpebral portion of the orbicularis oculi; it lies near the lid margin to maintain the margins next to the globe. The orbicularis oculi is the major muscle responsible for closing the eyelids.
A central retinal artery occlusion (CRAO) causes tremendous damage to the retina. How will the electroretinogram (ERG) of a person who has suffered a CRAO be affected? A.The a-wave will remain while the b-wave will disappear B.The a-wave will disappear while the b-wave will remain C.Both the a-wave and the b-wave will remain D.Both the a-wave and the b-wave will disappear
A.The a-wave will remain while the b-wave will disappear Explanation A central retinal artery occlusion will cause a loss of the b-wave which is formed by responses from the bipolar and Muller cells, both of which are nourished by the central retinal artery. The a-wave results from excitation of the photoreceptors. The a-wave will not be lost in the event of a CRAO due to the fact that photoreceptors receive their oxygen supply via the choroid.
Which of the following will occur if you increase the water content of a soft hydrogel contact lens? A.The patient will report an increase in dry eye symptoms B.The oxygen permeability will decrease C.The tendency of lens deposits will decrease D.The lens durability will increase
A.The patient will report an increase in dry eye symptoms Explanation As the water content of a soft hydrogel contact lens increases, generally the durability of the lens will decrease, the permeability of the lens will increase as will deposit formation and dry eye symptoms. This is also mostly try for silicone-hydrogel lenses, except for the fact that with these lenses, as water content increases, the permeability of the lens tends to decrease.
Which of the following BEST describes the definition of irregular astigmatism? A.The principal meridians of the cornea are not perpendicular to each other B.The axis of astigmatism is located along an oblique axis C.The principal meridians of the cornea are located 90 degrees apart D.The axis of astigmatism is located along the 90 degree meridian
A.The principal meridians of the cornea are not perpendicular to each other Explanation Astigmatism can be classified as either being regular or irregular. Regular astigmatism occurs in individuals in which the principal meridians of the cornea are located 90 degrees apart. That is, the area of the cornea with the flattest curvature (the axis) is oriented perpendicular to the meridian of the steepest curvature. In certain ocular conditions such as ker`atoconus, corneal scarring, or post-surgical corneas, the steep and flat meridians may not be oriented 90 degrees apart. This type of corneal curvature can be considered irregular astigmatism. In these cases, the refractive error is typically not well corrected with spectacles, in comparison to correction with gas-permeable contact lenses.
While examining a patient with diplopia, you ask him to look downward and toward his nose. He is able to move the eye toward his nose (medially) but not down. Based on the isolated agonist model of eye movement by extraocular muscles, which nerve and muscle are not functioning appropriately? A.Trochlear nerve, superior oblique B.Oculomotor nerve, superior rectus C.Abducens nerve, inferior oblique D.Abducens nerve, lateral rectus E.Trochlear nerve, inferior oblique
A.Trochlear nerve, superior oblique Explanation The trochlear nerve (CN IV) innervates the superior oblique muscle. The abducens nerve (CN VI) innervates the lateral rectus, which is not involved in the motion described in this question. The oculomotor nerve has two divisions; the inferior division innervates the inferior rectus, inferior oblique and medial rectus, while the superior division innervates the superior rectus and levator palpebrae superioris. The functions and anatomy of the extraocular muscles are as follows: Superior rectus - turns eye up, adducts, and medially rotates (intorsion) Inferior rectus - turns down, adducts, and laterally rotates (extorsion) Lateral rectus - abducts eye (laterally) Medial rectus - adducts eye (medially) Superior oblique - medially rotates (intorsion), abducts and turns eye down Inferior oblique - laterally rotates (extorsion), abducts and turns eye up In the case described here, when the patient adducts the eye medially with the medial rectus as well as the superior and inferior rectus, only the superior oblique and inferior oblique can move the eye down or up respectively because the superior and inferior rectus muscles are already contracted. The same is true if a patient abducts the eye with the obliques and lateral rectus: only the superior and inferior rectus can move the eye up or down respectively.
A patient is seen at your office reporting constant diplopia. The patient notes that the diplopia is still present when you cover her right eye. Based upon this information, what is the MOST likely etiology of her diplopia? A.Uncorrected refractive error B.Lateral rectus palsy C.Superior oblique palsy D.Aneurysm
A.Uncorrected refractive error Explanation Monocular diplopia is never caused by any type of cranial nerve dysfunction. The most common cause of monocular diplopia is an uncorrected refractive error. Other causes of monocular diplopia include corneal irregularities, lens irregularities, lens subluxation (very rare), or an improper glasses prescription. Whenever you are confronted with a recent onset of diplopia, the first thing you must determine is whether the diplopia is present monocularly or binocularly.
Which of the following methods can be used to test for the presence of eccentric fixation? A.Visuoscopy B.The Hirschberg test C.Binocular versions D.The Bruckner test
A.Visuoscopy Explanation Angle Kappa (Lambda), visuoscopy, Haidinger's Brush, and the Brock-Givner afterimage transfer tests are all methods of investigating for the presence of monocular fixation. The Hirschberg test allows for the determination of the direction, magnitude, and frequency of the ocular deviation. The Bruckner test may be used to detect small angle deviations, media opacities, anisometropia, and tumors. Binocular versions allows for the determination of the comitancy of the deviation.
whats weill-machesani
AD CT disorder -sublux (bilateral, inferior) RD short stature, small stubby hands+limbs
whats Fleck dystrophy
AD stromal, 1st decade fleck or comma-like depo of GAGs in stroma rarely needs any intervention
Vogt - Koyonagi - Harada syndrome, VKH
AI disease that attacks melanocytes. Ear, skin, meninges and uveal tissue
Pred formulations that don't need to be shaken?
AK-Pred Inflamase Mild Inflamase Forte
TCA cycle
AKA Kreb's. Occurs in the mitochondria.
Prior to cataract surgery, you accidently compress the cornea while performing an A-scan to measure the axial length of your patient. How will this affect the post-operative refractive error?
Accidental compression of the cornea while measuring the axial length will artificially shorten the eye's length measurement. A decreased axial length reading will alter the values that are used to calculate the required intraocular lens (IOL) power, causing an IOL with a higher plus dioptric power to be implanted. The outcome will result in a greater magnitude of post-operative myopia than expected.
Roid penetration
Acetate penetrates best, followed by alcohol and then phosphate, assuming an intact epithelium. In the absence of epithelium, phosphate penetration increases dramatically
Where do these drugs act on kidney: Hthiazide Furosemide Acetazolamide
Acetazolamide - PCT Hthiazide - early DCT (block Na/Cl pump + keeps Ca) Furosemide - thick ascending loop (blocks Na/2Cl/K cotransport)
Drug to be careful to use in sickle cell pts and why?
Acetazolamide / CAIs - can lead to metab acidosis --> further sickling of cells
What makes up a ketone body?
Acetoacetate D-hydroxybutyrate Acetone
Prism thinning
Adding base up to high powered minus lenses, results in overall decrease in lens thickness. Can also be used to decrease the center thickness of PAL's with plus powered lenses or with high add powers, unclear whether or not this is BU or BD (probs BD)
Corneal subepithelial infiltrates are linked with
Adenoviral keratoconjunctivitis Corneal graft rejection Contact lens solution hypersensitivity (type IV)
What blood tests is used in the analysis of liver function
Alanine and aspartate transminase (ALT & AST) Bilirubin levels Alkaline phosphatase (ALP)
Liver test to run to track treatment effectiveness in acute liver disease/hepatitis?
Alanine transaminase levels (ALT)
Research has recently discovered ocular signs associated with Alzheimer's disease. Which of the following two findings display a correlation with Alzheimer's disease? (Select 2) A) Afferent pupillary defects B) Amyloid deposits on/in the crystalline lens C) Thinner nerve fiber layer D) Infarctions of the conjunctival vessels E) Pigment epithelial detachments F) Peripheral chorioretinal degeneration
B) Amyloid deposits on/in the crystalline lens C) Thinner nerve fiber layer
In general, which of the following statements holds true regarding the relationship between center thickness and radius of curvature for gas-permeable lenses (assuming prescription and overall diameter remain constant)? A) There is no correlation between radius of curvature and center thickness B) As the radius of curvature becomes steeper, the center thickness increases C) As the radius of curvature steepens, the center thickness decreases D) As the radius of curvature becomes less steep, the center thickness increases
B) As the radius of curvature becomes steeper, the center thickness increases
Which 3 of the following clinical observations will aid in the confirmation of a diagnosis of nodular episcleritis? (Select 3) A) Nodule is usually tender to touch B) Associated congested blood vessels blanch with phenylephrine C) Associated congested blood vessels do not blanch with phenylephrine D) Nodule is not usually tender to touch E) Nodule can be moved over the underlying sclera F) Nodule cannot be moved over the underlying sclera
B) Associated congested blood vessels blanch with phenylephrine D) Nodule is not usually tender to touch E) Nodule can be moved over the underlying sclera
How is visual acuity impacted as the velocity of a moving stimulus is increased? A) As soon as the target begins moving, acuity declines at a rapid pace B) It remains constant until the target reaches a speed of roughly 60 degrees per second C) Acuity remains unchanged regardless of target speed D) Acuity degrades rapidly for slowly moving targets but remains unchanged for high-velocity stimuli
B) It remains constant until the target reaches a speed of roughly 60 degrees per second
Which 2 of these sentences about the lamina cribrosa pores of a healthy optic nerve head are TRUE? (Select 2) A) Lamina cribrosa pores are present only along the outer rim tissue B) Lamina cribrosa pores are larger superiorly and inferiorly when compared to nasally and temporally C) The number of pores of the lamina cribrosa increases with glaucomatous damage D) Lamina cribrosa pores are round in healthy eyes
B) Lamina cribrosa pores are larger superiorly and inferiorly when compared to nasally and temporally D) Lamina cribrosa pores are round in healthy eyes
Antibiotic resistance that is rapidly spread within a population of bacteria is due to what mechanism? A. Binary fission B. Conjugation C. Transformation D. Budding
B. Conjugation occurs between a donor (possesses a conjugative plasmid) and recipient bacteria. The donor bacterium initiates contact with the recipient via a sex pilus, allowing for cell-to-cell contact and transfer of DNA. The plasmids often contain genes that encode for toxin production, virulence factors, and antibiotic resistance. Genetic transformation is achieved by very few strains of bacteria and may only occur during certain phases of growth; therefore, rapid antibiotic resistance is not feasible. Budding and binary fission are means of reproduction but are not directly responsible for antibacterial resistance. Genes must have been transferred that code for resistance prior to budding and binary fission in order for the progeny to contain genes that allow for drug resistance.
Which of the following types of refractive error would have the greatest tendency to lead to amblyopia? A. A four-year old girl with an uncorrected refractive error of OD: +1.00-1.50 x 180 and OS: +1.50-1.25 x 180 B. A four-year old boy with an uncorrected refractive error of OD: +6.00 DS and OS: +1.50 DS C. A five-year old girl with an uncorrected refractive error of OD: -3.25 DS and OS: -0.75 DS D. A three-year old boy with an uncorrected refractive error of OD: +1.50 DS and OS: -2.00 DS
B. A four-year old boy with an uncorrected refractive error of OD: +6.00 DS and OS: +1.50 DS Explanation A prescription in which there is a big refractive difference between the eyes, especially if both eyes are hyperopic, is most likely to cause amblyopia. Consider the prescription of OD: +6.00 DS and OS: +1.50 DS. The left eye will be able to accommodate 1.50 diopters to obtain a clear distance image and, because accommodation is bilateral and equal, the right eye will still be 4.50 diopters out of focus. This defocus will cause the left eye to dominate the cortical neurons, causing a decreased amount of binocular neurons and leading to poor stereopsis and amblyopia of the right eye.
The visual acuity of a 77 year-old female patient with age-related macular degeneration is 2/16 in the right eye on the ETDRS chart. Why is this chart useful in monitoring the response to treatment with anti-vascular endothelial growth factor (VEGF)? A. Each line is 1.0 log units larger than the previous line B. Each line has 5 Sloan letters throughout the chart with equal spacing and is 1.26 times larger than the line below it; each line is .1 log units larger than the line below it when moving up the chart C. A three-line decrease represents a factor of a two time decrease in the size of the letters D. The Snellen construction of the chart enables the examiner to quickly note that a two-line increment represents a factor of a two time increase in the size of the letters
B. Each line has 5 Sloan letters throughout the chart with equal spacing and is 1.26 times larger than the line below it; each line is .1 log units larger than the line below it when moving up the chart Explanation The ETDRS chart is a logarithmic eye chart modeled after the Bailey-Lovie chart. It is the primary standardized eye chart used in evaluating the visual acuity of low vision patients. The ETDRS charts are logMAR (log of the minimum angle of resolution) in design and are constructed with 10 Sloan sans serif letters. Each line is 1.26 times larger than the line below, and the construction of each line is such that the difficulty is theoretically equivalent on every line. The construction of the ETDRS chart is made to eliminate the inherent errors in the measurement of visual acuity found in the traditional non-standardized Snellen test charts. The Snellen test charts have variations in legibility of different letters as well as differences in the spacing between the lines of letters and between adjacent letters on single lines. The ETDRS logarithmic chart is constructed in such a way that each line of letters is 0.1 log units (about 1.26 times) larger than the previous line. This is a geometric progression.
A patient brings you an old pair of glasses and asks you how much prism is in the lenses. With the lensometer, you measure 7 prism diopters base up and 4 base out in the right eye and 4 prism diopters base up and 5 base out in the left eye. What is the total amount of prism in the glasses? A.11 prism diopters base up total and 9 base out B.3 prism diopters base up in the right eye and 9 base out C.11 prism diopters base up total and 1 base out D.3 prism diopters base up in the right eye and 1 base out
B.3 prism diopters base up in the right eye and 9 base out Explanation For vertical prism, if the bases are oriented in the same direction, they will cancel each other out. When the bases are oriented in opposite directions in the vertical meridian (i.e., base up and base down), the powers will add together. The opposite holds true for prisms with their bases oriented horizontally. If the prism bases are both base out or base in, the powers are additive, while if they are opposite (that is, one is base in and one is base out), the powers will cancel.
Which one of the following bitoric GP contact lenses would NOT induce cylinder if rotated to a misaligned position on the eye? A.7.58 mm / -5.37 D - 8.18 mm / -0.50 D B.7.63 mm / -1.50 D - 8.11 mm / +1.12 D C.7.46 mm / -4.25 D - 8.13 mm / -1.75 D D.All of the options listed would induce cylinder if rotated off axis E.7.54 mm / +1.50 D - 7.99 mm / +2.75 D
B.7.63 mm / -1.50 D - 8.11 mm / +1.12 D Explanation Cylinder power effect (CPE) bitoric and base curve toric (with a spherical front-surface) gas-permeable (GP) lenses will induce unwanted cylinder if the lens rotates off axis. The resulting cylinder is due to cross-cylinder effects. However, a spherical power effect (bitoric) will not induce unwanted cylinder regardless of lens rotation. To determine whether a GP lens is a spherical power effect (SPE) or cylinder power effect (CPE) bitoric, measure the two base curves using a radiuscope and the two raw contact lens powers using a lensometer. If the difference between the two base curve meridians in diopters is the same as the difference between the two raw powers, the lens is an SPE bitoric. This is the case for only one of the above answers. Converting mm of base curve radius to diopters results in 7.63 mm = 44.25 D and 8.11 mm = 41.62; a difference of 2.62 D. The difference between the two raw powers of +1.12 D and -1.50 D is also 2.62 D. Therefore, this lens is a spherical power effect (SPE) bitoric GP contact lens.
A 32-year old female is seen at your office complaining of a recent onset of blurred vision, only at a distance. A thorough case history reveals that she recently began taking a new medication which you correctly assume has induced myopia. Which of the following medications is MOST likely to be the culprit? A.Tylenol® (acetaminophen) B.Accutane® (isotretinoin) C.Tums® (calcium carbonate) D.Omega III fish oil capsules
B.Accutane® (isotretinoin) Explanation Isotretinoin, birth control pills, and diuretics, among many other drugs, can cause myopia in some patients. Myopia most likely results from corneal swelling, which steepens the curvature of the cornea. Drugs that cause swelling of the lens, accommodative spasm, or edema of the ciliary body will also result in myopia. A reduction in the dose of the medication or cessation of the offending drug will usually result in reversal of nearsightedness. Fish oil, Tylenol®, and Tums® have not been shown to have a correlation with transient myopia development.
Which of the following drugs decrease intraocular pressure by increasing uveoscleral outflow? A.Dorzolamide B.Brimonidine C.Brinzolamide D.Pilocarpine E.Timolol
B.Brimonidine Explanation Glaucoma medications lower intraocular pressure by either decreasing aqueous production or by increasing aqueous outflow. There are three classes of drugs for which the mechanism of action is increasing aqueous outflow: cholinergic agonists, prostaglandin analogs, and alpha-2 agonists. Cholinergic agonists, such as pilocarpine, work by increasing trabecular outflow, whereas prostaglandin analogs and alpha-2 agonists work by increasing uveoscleral outflow. The other classes of glaucoma medications, such as beta-blockers and carbonic anhydrase inhibitors, work by decreasing aqueous production. It is important to note that alpha-2 agonists, such as Brimonidine (Alphagan®) and Apraclonidine (Iopidine®), have dual mechanisms of action. This class of medication decreases intraocular pressure by both increasing uveoscleral outflow and decreasing aqueous production.
What term describes the phenomenon in which a bacterium directs its movement TOWARD a chemical in its environment? A.Apoptosis B.Chemotaxis C.Phagocytosis D.Transposition
B.Chemotaxis Explanation Many bacteria possess flagella, or thread-like appendages, which allow for movement. Certain chemicals attract bacteria (chemoattractants), while others repel them (chemorepellents). Chemotaxis refers to the response of the bacteria to either chemoattractants or chemorepellents. In the absence of either of the aforementioned chemicals, bacteria will move in random patterns. Some bacteria possess genes and proteins which allow for the sensing of concentration gradients in their environment. In the presence of a chemoattractant, bacteria will have longer runs in the appropriate direction. Apoptosis is defined as programmed cell death. Phagocytosis refers to the engulfment of a particle (for example, bacteria) by a phagocyte (for example, a macrophage). Transposition refers to the rare phenomenon in which genes move from one place on the genome to another position.
What is the MOST common type of oculomotor deviation? A.Esophoria B.Exophoria C.Hyperphoria D.Hypophoria
B.Exophoria Explanation By far the most common oculomotor deviations are exo in nature ( about 95%), however most do not pose a problem. The least common type of deviation is vertical.
According to the Keith-Wagener-Barker method of classification, hypertensive retinopathy is categorized as stage four when which ocular sign is present? A.Flame hemorrhages B.Swelling of the optic disc C.Hard exudates in a star configuration D.Retinal edema
B.Swelling of the optic disc Explanation Grading of hypertensive retinopathy according to the Keith-Wagener-Barker system is as follows: Stage 1- narrowing of the retinal arteries Stage 2- stage 1, plus focal constriction of the retinal vasculature (arteriovenous nicking) Stage 3- stage 2, plus retinal hemorrhages, hard exudates (likely in a star configuration), cotton wool spots, and retinal edema Stage 4- stage 3, plus swelling of the optic disc. This patient must be hospitalized immediately
Drusen typically deposit between which layers of the retina? A.The inner and outer plexiform layers B.The retinal pigment epithelium and Bruch's membrane C.The ganglion cell layer and the nerve fiber layer D.The inner and outer nuclear layers
B.The retinal pigment epithelium and Bruch's membrane Explanation Drusen deposits collect between the retinal pigment epithelium (RPE) and Bruch's membrane. The retinal pigment epithelium plays a very important role in phagocytosis of shed outer segments of photoreceptors. If the RPE fails to rid the retina of this debris, it will begin to accumulate, which can have a significant impact on vision and may lead to macular degeneration.
Illumination is one of the most important considerations to discuss in the case disposition for a visually impaired patient. A patient with chronic open angle glaucoma moves a 60 watt bulb on a flexible mounted arm from three feet to one foot from the page. The illumination on the page will appear to have been increased by how much? A.Should be the same brightness B.Increased by 9 times the original brightness C.Increased by 3 times the original brightness D.Decreased by 1/9 of the original brightness E.Decreased by 1/3 of the original brightness
B.Increased by 9 times the original brightness Explanation It has been said that prescribed optical devices without consideration of the appropriate lighting will often doom the patient to failure. Unfortunately, there are no good tests to determine the exact type of lighting. Generally, different light levels are tried during the examination (as well as during the training session) with the patient using an adjustable light. The distance from the page is very important because of the inverse-square law of illumination: the intensity varies inversely as the square of the distance from the page. If the light is moved from 1 foot to 3 feet from the page, a bulb will be needed that is approximately nine times as bright to keep the same illumination on the page. (It should be noted that technically, this relationship is only true for a point source of light.) Clinically, however, it gives a good approximation of the change in brightness (illumination) seen on the page when the distance of the light is changed. The illumination in the above example would therefore increase by 9X when the bulb is moved towards the page.
A contracting muscle that develops tension but does not shorten displays which type of muscle tension? A.Isotonic B.Isometric C.Isovelocity D.Isovolume
B.Isometric Explanation Isometric contraction occurs when a muscle is contracting but is not shortening. This type of muscle tension is used for load-bearing situations such as holding a plate of food in front of you. Muscles that shorten but maintain the same amount of tension are said to display isotonic contraction. An isovelocity contraction follows when the force of the contraction varies while the velocity remains constant.
Which of the following skin conditions is considered to be benign and has the LOWEST risk of malignancy? A.Actinic keratosis B.Keratoacanthoma C.Squamous cell carcinoma D.Basal cell carcinoma
B.Keratoacanthoma Explanation Keratoacanthoma appears very much like squamous cell carcinoma (SCC) in that it tends to progress rapidly and appears to ulcerate. This condition typically occurs in middle-aged and elderly patients of Caucasian descent on areas of the skin that are exposed. The lesion appears elevated, and eventually the center will produce a scab-like plug of keratin. The margins surrounding the plug will be rolled. At some point the keratin plug will fall out, resulting in the formation of a pit, and the lesion will regress. Most patients and clinicians do not like to wait this condition out due to its similarities to SCC. Actinic keratosis is a pre-cursor to squamous cell carcinoma and appears as scaly, dry skin that does not heal. People with skin that is of lighter pigmentation along with excessive exposure to ultraviolet light tend to be most at risk for development of this condition. Squamous cell carcinoma (SSC) is thankfully one of the rarest malignancies but due to its ability to metastasize can be quite dangerous. This malignancy has the ability to progress rapidly and has a high affinity for people who spend a lot of time in the sun, especially those who are light-skinned. The only way to definitively diagnose SCC is to refer for a biopsy and ensuring the use of Mohs technique. This strategy takes more time but ensures that the lesion is removed. Essentially, Mohs procedure calls for removal of tissue and biopsy of the surrounding borders. If the borders prove to be malignant then more tissue is removed and biopsied. This continues until the borders prove to be free of any carcinoma. Basal cell carcinoma (BCC) is the most common malignant lid lesion and mercifully tends to be very slow-growing. BCC generally appears as a waxy, translucent nodule. Eventually the nodule will ulcerate. Patients may bring these to your attention and tell you that they have "had it for years and it just does not seem to heal". Whenever you hear this it is best to send out for biopsy via Mohs technique. BCC very rarely metastasizes.
Which of the following muscle pairings and actions follows Sherrington's law of reciprocal innervation? A.Looking to the right causes contraction of the right medial rectus and contraction of the left medial rectus B.Looking to the right causes contraction of the right lateral rectus and inhibition of the right medial rectus C.Looking to the right causes contraction of the right lateral rectus and inhibition of the left medial rectus D.Looking to the right causes contraction of the right medial rectus and inhibition of the right lateral rectus
B.Looking to the right causes contraction of the right lateral rectus and inhibition of the right medial rectus Explanation Sherrington's law of reciprocal innervation states that when a muscle is stimulated to contract, its antagonist is inhibited. Based upon this law, looking to the right causes contraction of the right lateral rectus and inhibition of the right medial rectus.
Which type of anterior scleritis is associated with the highest risk of perforation? A.Diffuse B.Necrotizing D.Scleromalacia perforans E.Nodular
B.Necrotizing Explanation Scleritis is an inflammation of the sclera that generally occurs secondarily to a systemic condition, usually of collagen vascular origin. Diffuse scleritis has a gradual onset and presents as a boring pain which may radiate to other structures such as the jaw and forehead. Patients will present with distension of the scleral vascular pattern, causing a deep pinkish hue of the sclera. Nodular scleritis appears similar to diffuse scleritis, but the areas of inflammation are localized to painful, raised nodules. Scleromalacia perforans is the least common form and is almost always seen in association with rheumatoid arthritis. Patients with scleromalacia perforans generally do not experience pain or inflammation. Necrotizing scleritis is the most severe form and has a higher mortality rate than the other types due to the fact that it usually stems from autoimmune diseases.
What type of agar is commonly used to culture fungi? A.Cetrimide agar B.Sabouraud's agar C.Blood agar plate D.Thayer-Martin agar E.Hay infusion agar
B.Sabouraud's agar Explanation Sabouraud's agar is useful for culturing fungi. Culturing and sensitivity testing are important diagnostic tools used to determine the offending pathogen and help to select the appropriate medication for treatment. Sabouraud's agar is unique in that it possesses a low pH that causes the inhibition of most bacterial growth, allowing for better isolation of the fungus. Hay infusion agar is frequently utilized to culture slime moulds. Cetrimide agar is designed to isolate Gram-negative bacteria. Blood agar plates are useful for the detection of pathogenic organisms via the presence of hemolytic activity (the ability of organisms to lyse or destroy red blood cells). Blood agar plates are not a selective medium, as many different types of organisms are capable of growth on this type of agar. Thayer-Martin agar is a type of chocolate agar used to isolate Neisseria gonorrhoeae.
Bipolar cells receive information from photoreceptors. Which type of neurotransmitter do bipolar cells respond to? A.Glycine B.Serotonin C.Glutamate D.Dopamine
C.Glutamate Explanation Bipolar cells respond to glutamate released by photoreceptor cells. Glutamate release in the dark causes on-center bipolar cells to hyperpolarize (inhibition) and off-center bipolar cells to depolarize (excitation).
Which layer of the cornea, if penetrated, will leave a scar? A.The wing cell layer B.The stroma C.The tear film D.The epithelium
B.The stroma Explanation The corneal epithelium is comprised of 3 major layers. The outermost layer is composed of superficial cells (2-3 layers) followed by wing cells (2-3 layers) and, lastly, basal cells (1 layer). Damage to the epithelium will heal without keloid formation. The epithelial basement membrane is made up of collagen types IV, VII and XII. The stroma makes up the bulk of the cornea and is comprised of keratocytes, nerves, type I collagen fibers and mucopolysaccharides. If injured, the stroma will heal but a scar will remain at the site of trauma. The tear film lies anterior to the cornea and is not composed of tissue and as such cannot scar, nor is it considered a part of the cornea
In order to determine which design of toric gas-permeable contact lens you have once the lens has been analyzed, the difference in base curve (BC) values and contact lens power (CLP) readings must be calculated first.
BC1 = 7.58 = 337.5/7.58 = 44.50 BC2 = 7.84 = 337.5/7.84 = 43.00 Change in BC = 1.50 D CLP1 = -1.00 CLP2 = -2.50 Change in CLP = 1.50 D The differences in base curves and contact lens powers for the above gas-permeable contact lens are equal (both 1.50 D), indicating that the design of the lens is a spherical power effect (SPE) bitoric type.
BCC affects which layer SCC affects? appearance of each
BCC = stratum basal SCC = stratum spinosum BCC = shiny firm nodule + telangectasia --rodent ulcer when advanced SCC = scaly pink/red BASAL CELL IS 50X MORE COMMON
Which of the following conditions are associated with a lesion involving the third nerve fasciculus?
Benedikt syndrome involves the fasciculus as the fibers pass through the red nucleus. Patients will develop an ipsilateral third nerve palsy with contralateral extrapyramidal signs (such as hemitremor). Weber syndrome involves the fascicular fibers as they pass through the cerebral peduncle. Signs include ipsilateral third nerve palsy with contralateral hemiparesis. Nothnagel syndrome involves the superior cerebral peduncle and the fasciculus. It is characterized by ipsilateral third nerve palsy as well as cerebellar ataxia. Claude syndrome is a combination of both Benedikt and Nothnagel syndromes.
A father brings in his two-year old son for evaluation at your office. The father remarks that his son was born with what appears as a small red birthmark on his forehead. He wishes to know if it requires treatment or warrants removal. Applying pressure over the area of interest causes blanching of the lesion, and the father reports that the birthmark appears darker when his son cries. What is your prognosis? Malignant and requires immediate biopsy Benign but is likely to be permanent and will darken will time Benign and will likely regress by the time the child is 5 years of age A pre-cursor to a malignant condition and will continue to increase in size with time
Benign and will likely regress by the time the child is 5 years of age The above findings describe a capillary hemangioma (also called a strawberry mark), which is a patch of blood vessels or a vascular birthmark. Most hemangiomas occur at birth or shortly thereafter. There are several different types of hemangiomas, but the most common is the capillary type. The capillary hemangioma will blanch with applied pressure and tends to change color with Valsalva maneuvers, crying, or straining due to changes in blood flow. The majority of these types of vascular lesions will regress by the time the child is 5 years old. If the lesion is still present past puberty, then the lesion is likely permanent and may be removed if the patient is unhappy with the cosmesis.
What is the main mechanism of action of fluticasone and salmeterol, which are components found in Advair®, respectively? A. Anti-inflammatory; leukotriene inhibitor B. Bronchodilator; anti-inflammatory C. Anti-inflammatory; bronchodilator D. Anti-histamine; anti-inflammatory E. Anti-inflammatory; anti-histamine F. Leukotriene inhibitor; anti-inflammatory
C. Fluticasone is a synthetic corticosteroid that has a very potent anti-inflammatory action. Inflammation plays an important role in the pathogenesis of asthma; therefore, this anti-inflammatory is very effective in helping to control asthmatic complications. As is the case with all other steroids, patients using Advair® should be examined periodically to monitor intraocular pressure and possible development of cataracts. Salmeterol is a long-acting beta2-adrenergic agonist. Beta2-adrenoceptors are the predominant adrenergic receptors involved in bronchial smooth muscle, with little association to the heart. Salmeterol acts to increase the levels of circulating cyclic AMP in the bloodstream; this causes relaxation of bronchial smooth muscle and inhibition of the release of mediators of immediate hypersensitivity from cells (especially mast cells).
Congenital cataracts can be caused by a viral infection of the mother with rubella virus (German measles) during development of the primary lens fibers. At which time period in embryonic development can infection cause congenital cataracts? A.2nd trimester B.Conception C.1st trimester D.3rd trimester E.Post-delivery
C.1st trimester Explanation The developing lens is susceptible to rubella virus when the lens fibers are forming, which occurs around weeks 4-7 of gestation. Earlier infection will occur prior to lens fiber development, and the lens is resistant to later infection because the virus is unable to penetrate the lens capsule. The fetus is most susceptible to lenticular damage during the first trimester. Contraction of the rubella virus will cause the greatest amount of damage during this time period. Congenital cataracts are usually detectable at birth but may be seen later because the virus can persist in the lens.
A patient who has a high spatial frequency cut-off of 40 cycles per degree will have what predicted Snellen acuity? A.20/30 B.20/40 C.20/15 D.20/20
C.20/15 Explanation In order to convert from cycles per degree to Snellen acuity, simply divide 600 by the cycles per degree; this will solve for the denominator of the Snellen acuity. For the above example 600/40 = 15. Therefore, the predicted Snellen acuity would be 20/15.
While performing the astigmatic clock dial, your patient reports that the clearest/blackest line is the 2-8 line while the 5-11 line is the least clear. What would be the corresponding axis of astigmatism? A.150 degrees B.30 degrees C.60 degrees D.180 degrees
C.60 degrees Explanation In order to determine the corresponding axis of astigmatism utilizing the clock dial, one must multiply the smallest number of the clearest clock position by 30 degrees. In our case 2 x 30= 60 degrees. In general the line perpendicular to the clearest line is generally the least clear as this corresponds to the second principal meridian of the eye. Remember the principal meridians of the eye are 90 degrees apart.
Which of the following is a precursor to steroid hormones such as testosterone? A.Phospholipids B.Triglycerides C.Cholesterol D.Sphingolipids
C.Cholesterol Explanation Progesterone, aldosterone, testosterone, estradiol and cortisol are all derived from cholesterol. Cholesterol has a unique configuration comprised of four joined cycloalkane rings. Because these hormones are fat-soluble, they readily pass through cell membranes. They diffuse into the blood and are generally bound to carrier proteins, which transport the hormones to their designated target site where they may further undergo processing or transformation. Sphingolipids are important in cell membranes, especially those located in the central nervous system, such as myelin sheath. Sphingolipids contain sphingosine as a backbone and are then further classified depending on which molecules are attached to that backbone, such as ceremides, gangliosides, sphingomyelin, etc. Phospholipids contain a polar and non-polar end, thus making them amphoteric. This property allows for the formation of bilayers (polar ends aligned together and pointed outwards) resulting in the lipid bilayer commonly seen in cell membranes. Phospholipids are generally comprised of a phosphate group, a choline group (polar), and two fatty acid chains (non-polar) attached to glycerol, which serves as the backbone. Triglycerides are comprised of three fatty acid chains attached to a glycerol backbone. Triglycerides are important in long-term energy storage for use by cells.
Which of the following is the correct pathway for the drainage of tears through the nasolacrimal drainage system? A.Nasolacrimal duct, lacrimal sac, valve of Hasner, lacrimal canaliculus, ampulla, lacrimal punctum B.Lacrimal sac, lacrimal punctum, lacrimal canaliculus, ampulla, nasolacrimal duct, valve of Hasner C.Lacrimal punctum, lacrimal canaliculus, ampulla, lacrimal sac, nasolacrimal duct, valve of Hasner D.Lacrimal punctum, lacrimal canaliculus, ampulla, valve of Hasner, nasolacrimal duct, lacrimal sac
C.Lacrimal punctum, lacrimal canaliculus, ampulla, lacrimal sac, nasolacrimal duct, valve of Hasner Explanation The lacrimal punctum is a small aperture located in the lacrimal papilla, the slight elevation at the junction of the lacrimal and ciliary portions of the eyelid margin. Initially, the tear film drains through this aperture. The lacrimal punctum leads into the lacrimal canaliculus, the tube connecting the punctum to the lacrimal sac. The ampulla is a slight dilation in the initial portion of the lacrimal canaliculus. The canaliculi from the upper and lower lids run horizontally along the lid margin, connecting into a common canaliculus that then enters the lateral aspect of the lacrimal sac located in the anterior portion of the medial orbital wall. The lacrimal sac empties into the nasolacrimal duct in the maxillary bone. The valve of Hasner is located at the terminus of the nasolacrimal duct in the inferior nasal meatus. The Valve of Hasner is a fold of mucosal tissue that ensures that fluid flows anterograde out of the duct.
Midget ganglion cells receive information pre-synaptically from which cells? A.Flat bipolar cells B.Rod bipolar cells C.Midget bipolar cells D.Horizontal bipolar cells
C.Midget bipolar cells Explanation Midget bipolar cells synapse onto midget ganglion cells. These are very selective and exclusive channels as one cone cell synapses with one midget bipolar cell which then in turn relays the information to a midget ganglion cell. There is no additional input from other cells or synapses. These types of monosynaptic cells are most common in the central retina thus explaining the ability to visually discern fine details. Flat bipolar cells receive information from many cone cells and in turn synapse with many ganglion cells. Rod bipolar cells, as their name suggests, convey information from many rod cells to several ganglion cells. Rods relay information only to rod bipolar cells.
A cortical hypercolumn is comprised of which of the following? A.An ocular dominance column for one eye only and a complete set of orientation columns B.An ocular dominance column for one eye only and orientation columns for one specific orientation only C.Ocular dominance columns for both eyes and a complete set of orientation columns D.Ocular dominance columns for both eyes and orientation columns for one specific orientation only E.A complete set of ocular dominance columns for one eye only and a complete set of orientation columns
C.Ocular dominance columns for both eyes and a complete set of orientation columns Explanation The striate cortex is organized into discrete rows and columns that help to code for specifics of the stimulus. A hypercolumn consists of both a right and left eye ocular dominance column as well as orientation columns for every orientation. An electrode that penetrates the cortex perpendicularly will encounter cells with the same ocular dominance, and they all respond to stimuli of the same orientation. However, an electrode that penetrates the cortex parallel to its surface will encounter neurons that all possess the same ocular dominance but respond preferentially to stimuli of different orientations. In order for ocular dominance columns to form properly, it is essential that normal vision is present in both eyes during the early years of life.
Which of the following types of congenital cataracts are characteristic of galactosemia? A.Sunflower cataracts B.Blue dot (Cerulean) opacities C.Oil droplet opacities D.Christmas tree cataracts
C.Oil droplet opacities Explanation Central oil droplet opacities are a type of congenital cataract that is associated with galactosemia, a genetic metabolic disorder that affects the body's ability to metabolize galactose properly. Blue dot (Cerulean) opacities are congenital cataracts and are not usually associated with systemic disease but are thought to be due to autosomal dominant mutations in several genes. Christmas tree cataracts are not considered a congenital type of cataract; they are a rare variant of senile cataracts that have a strong association with myotonic dystrophy. Sunflower cataracts are also not considered congenital cataracts and are due to the abnormal deposition of copper in patients suffering from Wilson's disease.
A patient is seen at your office complaining that her right eye is physiologically higher than her left eye. She would like to know if glasses would help improve the cosmesis of her predicament. You know that prism will shift the image of an object. How would you orient a prism to help her appearance? A.Prescribe base out prism over the left eye B.Prescribe base down prism over the left eye C.Prescribe base up prism over the right eye D.Prescribe base in prism over the left eye
C.Prescribe base up prism over the right eye Explanation A prism will bend light towards its base, but the image will be shifted towards the apex of the prism. Therefore, by prescribing base up prism over her right eye, its image will be shifted down towards the apex of the prism. Another way of remembering this is to think of the prism as an arrow that will point in the direction of the deviation (i.e., exotropia is neutralized with base in prism, the eye points outwards, the apex of the prism also points out). Prescribing prism for cosmetic purposes may not always be an option as significant vertical prism may induce diplopia or visual discomfort. Dr. Goodfellow's explanation Most all of those rules of using prism to shift the observer's view pretty much assume that you are dealing with a patient that has a non-seeing eye. Otherwise, such prism would interfere with the patient's fusion. You are correct that if you are using prism for phoria purposes, that BD OS is equivalent to BU OD, but in the case of using prism in front of a non-seeing eye to make the eye appearance better, you would put all of the prism in front of just the problem eye. I also think the idea of physiologically higher eye means the entire eye socket is higher. It's not really the same as a hypertropia which might be able to be fixed the way you are thinking.
Which of the following alterations will help to loosen a tightly-fitting gas-permeable lens? A.Increase the overall diameter B.Reduce the width of the peripheral curve system C.Reduce the size of the optic zone D.Steepen the peripheral curve system E.Steepen the base curve of the lens
C.Reduce the size of the optic zone Explanation There are a multitude of alterations that can be made when a lens is fitting too tightly, many of which can be done in-office if a modification unit is available. If a gas-permeable lens is fit too tightly, the most commonly altered parameter is flattening of the base curve. One can also decrease the optic zone, decrease the overall diameter (OAD), widen the peripheral curve system, or flatten the peripheral curve system. In order to modify a lens that is fitting too loosely, simply reverse all of the above: steepen the base curve, increase the OAD, increase the optic zone, steepen the peripheral curve system, and narrow the width of the peripheral curves.
During gestation, when does the secondary vitreous begin to develop? A.The 20th week of gestation B.The 1st week of gestation C.The 9th week of gestation D.The 30th week of gestation
C.The 9th week of gestation Explanation The primary vitreous develops at around the third week of gestation. It is formed by mesoderm. The secondary vitreous begins to develop during the ninth embryonic week and later becomes the mature vitreous. The secondary vitreous stems from primary vitreal cells and retinal glial cells and therefore originates from neuroectoderm. The secondary vitreous expands to fill the globe while compacting the primary vitreous in the center of the globe.
Which of the following correctly describes the autonomic innervation of the iris muscles? A.The iris sphincter and iris dilator are both innervated parasympathetically B.The iris sphincter is innervated sympathetically and the iris dilator is innervated parasympathetically C.The iris sphincter is innervated parasympathetically and the iris dilator is innervated sympathetically D.The iris sphincter and iris dilator are both innervated sympathetically
C.The iris sphincter is innervated parasympathetically and the iris dilator is innervated sympathetically Explanation Stimulation of the sympathetic nervous system results in pupil dilation and the parasympathetic nervous system pupil constriction. Accordingly, the sphincter muscle (which constricts the pupil) is innervated by the parasympathetic nervous system and the dilator muscle (which dilates the pupil) is innervated by the sympathetic nervous system.
Berger's space is created by an interval between which two structures? A.The anterior face of the lens and the posterior surface of the iris B.The posterior surface of the cornea and the anterior face of the iris C.The posterior face of the lens and the anterior vitreous D.The equator of the lens and the ciliary body
C.The posterior face of the lens and the anterior vitreous Explanation: Berger's space is created by the separation between the posterior face of the lens and the anterior face of the vitreous. The space between the equator of the lens and the ciliary body is known as the circumlental space.
A constant ringing of the ears is known as which of the following terms? A.Otitis media B.Sinusitis C.Tinnitus D.Malleus
C.Tinnitus Explanation Tinnitus is caused by damage to hair cells in the inner ear from exposure to excessive noise, medications (like aspirin), aging, and some diseases. Sound waves cause the hair cells to bend, releasing a neurotransmitter and causing action potentials of the auditory nerve. Sometimes the hair cells break or are left in the "on" position, causing the perception of ringing. Otitis media is an infection or inflammation of the middle ear. Sinusitis is an inflammation of the sinuses. The malleus, also known as the hammer, is one of the tiny bones in the ear that help to transmit and amplify sound to the auditory nerve.
CN palsy most associated with idiopathic intracranial HTN
CN 6
A lesion of which CN would cause loss of taste from front of tongue
CN 7 (anterior 2/3)
what innervates parotid
CN 9
Which cranial nerves have their nuclei located in the midbrain?
CN III CN IV
Superior orbital fissure
CN III through CN VI. Everything that controls eyeball movement and lids except for CN VII. This is not entirely accurate
Which cranial nerves have their nuclei located in the medulla?
CN IX CN X CN XI CN XII
Which 4 of the following cranial nerves have their nuclei located in the pons? (Select 4) Cranial nerve III Cranial nerve VI Cranial nerve VIII Cranial nerve IV Cranial nerve VII Cranial nerve V
CN V CN VI CN VII CN VIII
Center thickness of RGP equation
CT = 0.023 x contact lens power + 0.19 mm *minimum center thickness for RGP = 0.12 mm*
A lens clock has many uses. Which items can be measured via a lens clock?
Calculate the base curve of an ophthalmic spectacle lens, determine the add power of a multifocal lens, test for potential lens warpage, determine the amount of slab-off prism on an ophthalmic lens, calculate the thickness of a gas-permeable lens as well as determine the nominal (or approximate) power of an ophthalmic lens.
Your patient has a telephone script he must follow when speaking to his customers. The letters are approximately 0.8M sized. What would the MOST appropriate power for a stand magnifier be for a working distance of 33cm, based upon his distance acuity?
Calculate the needed magnification based upon the acuity of the better eye. Calculate the reciprocal of vision (using a 20 foot acuity) and multiply by the reciprocal of the working distance. Remembering that 0.8M equals RS40, then: 400/40=10 1/0.33=3 D 10x3=30
mnemonic for 4 bacteria that invade intact epi
Canadian National Hockey League Cornybacterium diptheriae Neisseria gonorrhea Haemophilus Listeria=
Higher order aberrations
Cannot be corrected by lenses
A 23-year old female is seen at your office with concerns of eye fatigue, diplopia and headaches after 30 minutes of computer use. Her subjective refraction is +0.25 D OU. Her near point of convergence is 15 centimeters. What is the most likely diagnosis based solely upon this information? Brain tumor Convergence excess Latent hyperopia Convergence insufficiency
Convergence insufficiency The most notable of the exam findings is the near point of convergence (NPC) -generally one expects an NPC of less than 6cm (closer is better with NPC). Her NPC is receded to 15 cm. Normally, if patients display a receded NPC but they are asymptomatic, no treatment is necessary. In the above case, the patient is experiencing diplopia and asthenopia with prolonged near work which infers some type of intervention may be required (likely vision therapy). Brain tumors typically present as headaches that are present in the morning and worsen over a time period of weeks to months. Latent hyperopia normally presents as blurry vision and headaches with prolonged near work, but diplopia is generally absent.
Main cause of true membranous conjunctivitis
Corynebacterium diphtheria
Numerous reports have suggested that increased tear film osmolarity is a key consequence in dry eye. Although osmolarity is not easily measured in the clinical setting, tear osmolarity increases in most dry eye sub-types due to which of the following processes? A. In aqueous tear deficiency, the lacrimal gland produces more ionic species B. The lipid layer is altered in most dry eye states, leading to ion pairing C. Decreased capillary exchange leads to ionic bonding D. Loss of tear stability induces an increased evaporation rate, leading to increased osmolarity E. Reactive oxygen species are increased in the tears of most dry eye sub-types; this increases osmolarity F. Patients with dry eye tend to blink less than normals, leading to increased evaporation
D. Tear instability leads to greater evaporation and higher osmolarity through a mechanism of concentration of the remaining tears, since only the aqueous tear portion evaporates rather than the ionic species. Several studies have indicated that normal tear osmolarity is less than or equal to 300 Osm/L, with values exceeding 308 Osm/L indicating increased osmolarity. As a single measure, tear osmolarity has recently been found to correlate the best (r squared 0.55) to dry eye severity of several clinical tests in a large, multi-center study (Sullivan et al., IOVS 51:6125-6130, 2010).
The ligaments that suspend the lens (zonules) are embryonically derived from what structure? A. The lens capsule B. The primary vitreous C. The lens epithelium D. The tertiary vitreous
D. The zonules are attached to the posterior and anterior surfaces of the lens and connect to the pars plana of the ciliary body. The primary vitreous develops from weeks 3 through 9. The secondary vitreous then begins to form and condenses the primary vitreous forming Cloquet's canal. Developmentally, the tertiary vitreous is secreted last; the zonules are comprised of condensed tertiary vitreous.
A 12-year old male is sitting in your waiting room while his mother undergoes her annual eye exam. While waiting, he eats a candy bar containing peanuts, and, as luck would have it, he is deathly allergic to nuts. To counter anaphylactic shock, what would be the BEST course of action? A. Administration of Benadryl (oral) B. Olopatadine (Patanol) C. Prednisone (oral) D. Injection of epinephrine (EpiPen)
D. Anaphylactic shock is defined as a severe, multi-system, type I hypersensitive, acute allergic reaction that may be life-threatening. Signs of an allergic reaction include tingling, itching, hives, swelling of lips and tongue, constriction of the airway, vasodilation, myocardial depression, and a decrease in blood pressure. The EpiPen is injected intramuscularly to the upper lateral thigh to ensure rapid delivery. Epinephrine (Adrenaline) activates both alpha and beta adrenergic receptors causing an increase in peripheral vascular resistance and allowing for an increase in blood pressure and coronary artery perfusion. Adrenaline also serves to reverse vasodilation and decrease urticaria and angioedema. For severe, life-threatening reactions, Benadryl (diphenhydramine) will not work quickly enough. Topical antihistamines have little if any systemic absorption and therefore will not be effective in counteracting the anaphylaxis. While oral steroids may be useful in the post-management of anaphylactic shock, they will not yield the desired immediate response.
A common cause of epiphora in infants is caused by a small membrane that covers over which of the following structures? A. The lacrimal gland B. The puncta C. The canaliculus D. The valve of Hasner
D. It is common for mothers of young infants to note that one eye (or both eyes) of her infant constantly tears in conjunction with the presence of mucopurulent discharge. This epiphora results from a blockage of the nasolacrimal passageway caused by a membrane covering the valve of Hasner. The majority of blockages will self-resolve without intervention (80-90% of infants) within the first 12 months of life. Treatment may include massage of the nasolacrimal sac several times a day in an effort to rupture the membrane.
A 42-year old patient reports that her right eye has been watery and she has mild pain, redness, and swelling in the lower medial canthal region. You suspect dacryocystitis as the cause of her symptoms. Which of the following procedures is NOT appropriate when further evaluating this possible diagnosis? A. Exophthalmometry B. Extraocular muscle motility C. Digital palpation of the medial canthal area D. Dilation and irrigation of the lacrimal system E. Gram stain and blood agar cultures of discharge
D. The evaluation of a patient suspected of dacryocystitis should involve a detailed case history including a discussion of any previous episodes with similar symptoms, or the presence of any concomitant ear, nose, or throat irritation/infection. External examination of the patient should include the application of gentle pressure to the lacrimal sac region in order to attempt to express any discharge from the punctum; this should be done bilaterally. If any discharge can be recovered, a Gram stain or blood agar culture is helpful in determining the type of bacteria present. In addition to these tests, extraocular motility and evaluation for the presence of proptosis should be completed to rule out orbital cellulitis. In atypical, severe, or non-responding cases, a computed tomography scan (CT) should be considered. It is important to remember that probing, dilation, and/or irrigation of the lacrimal system should not be attempted during an acute infection of the lacrimal gland. This may cause the infection to spread to other areas such as the throat.
A convex mirror in water (n=1.33) has a radius of curvature of 12 cm. What is the dioptric power of the mirror? A.-11.08 D B.+8.33 D C.+22.17 D D.-22.17 D
D. -22.17 D Explanation A concave mirror converges light and therefore acts like a convex lens, hence concave mirrors have positive dioptric values whereas convex mirrors diverge light and possess negative dioptric powers. The equation used to determine the power of a mirror is P=-2n/r, where P= the power of the mirror in diopters, n= the index of refraction of the surrounding medium, and r= the radius of curvature of the mirror in meters. P=2(1.33)/-0.12=-22.17 D. Remember, a convex mirror will have a positive radius of curvature and a concave mirror will have a negative radius of curvature.
A patient is using a stand magnifier of +16D with a +2.00 add. If the distance separating the two lenses is 25 cm what is the equivalent power of this combination? A.26D B.22D C.18D D.10D
D. 10 D Explanation De= D1+D2 -tD1D2 where De=equivalent power;D1=power of magnifier;D2=power add;t=separation in meters between the lenses De = (16+2) - 0.25(16)(2) De= 18-8 = 10D 18D- incorrect answer -would come up with this if added the stand magnifier power to the power of the add 22D -incorrect answer - would come up with this if added 16D for stand mag 2D for add and 4D for equivalent of 25cm. 26D - if added the 18 +8 in the De equation instead of subtracting
What is the minimum thickness necessary for an antireflective coating (n=1.9) to be useful against incident light of 530 nm wavelength? A. 139.5 nm B. 278.9 nm C. 132.5 nm D. 69.7 nm E. 58.3 nm
D. 69.7 nm Explanation The equation for finding the minimum antireflective coating thickness is: thickness = wavelength/(4 x index of coating) thickness = 530 / (4 x 1.9) thickness = 530 / 7.6 thickness = 69.73 nm
Which of the following conditions would be categorized as causing amblyopia due to deprivation? A. A five-year old with an uncorrected prescription of OD: +7.00 D 20/400 OS: +0.50 20/20 B. A child born with a monocular 2 mm ptosis C. A three-year with a constant right 30 prism diopter esotropia D. A child born with a large congenital cataract in one eye only
D. A child born with a large congenital cataract in one eye only Explanation Form deprivation amblyopia results when a clear and focused retinal image is blocked to one eye during the critical period. This can occur by a complete congenital cataract in one eye, a large ptosis that covers most or all of the pupil or by some other element that occludes the eye. The lack of visual information to the retina causes the other eye (non-occluded eye) to become dominant and thusly have stronger and a greater number of synaptic connections to the brain. Amblyopia causes a disproportionate amount of cortical neurons to respond preferentially to the non-deprived eye. The occlusion must occur during the critical period, and the earlier the occlusion is detected and removed, the better the prognosis. A small ptosis (i.e. 2 mm) would not be expected to cause amblyopia because the pupil would not be occluded. An unequal prescription such as the one in the above question would cause anisometropic amblyopia in which one eye would receive a clear image while the other would receive a blurry image. The brain would favor the clear retinal image, resulting in a strong dominance of cortical neurons for the least ametropic eye. Strabismus results in the perception of two images that are not fusible by the brain, causing diplopia. In order to eliminate double vision, the eye will suppress an eye (usually the deviated eye). This suppression leads to amblyopia.
A common cause of epiphora in infants is caused by a small membrane that covers over which of the following structures? A. The lacrimal gland B. The puncta C. The canaliculus D. The valve of Hasner
D. The valve of Hasner Explanation It is common for mothers of young infants to note that one eye (or both eyes) of her infant constantly tears in conjunction with the presence of mucopurulent discharge. This epiphora results from a blockage of the nasolacrimal passageway caused by a membrane covering the valve of Hasner. The majority of blockages will self-resolve without intervention (80-90% of infants) within the first 12 months of life. Treatment may include massage of the nasolacrimal sac several times a day in an effort to rupture the membrane. Reference: Chern, K. and Wright K., Review Questions in Ophthalmology: A Question and Answer Book (2005) pp 241
A cranial nerve VI palsy will cause what type of deviation? A.Exodeviation worse with near viewing B.Esodeviation worse with near viewing C.Exodeviation worse with distance viewing D.Esodeviation worse with distance viewing
D.Esodeviation worse with distance viewing Explanation A cranial nerve (CN) VI palsy, or a palsy of the abducens nerve, will cause an esodiviation on the affected side and will result in horizontal diplopia, which worsens with distance viewing since this nerve innervates the lateral rectus muscle. The patient may present with a head turn towards the same side as the affected eye. For instance, if the patient has a right lateral rectus palsy, he or she may present with a head turn to the right to help eliminate diplopia. It helps to think in terms of function. The lateral recti serve to abduct the eyes, and distance viewing requires divergence, or a turning out of both eyes simultaneously. A CN VI palsy will therefore be more evident when the patient looks far away, because the eye cannot abduct.
A healthy retinal nerve fiber layer is thickest at which portion of the optic nerve head? A.Nasally B.Temporally C.Superiorly D.Inferiorly
D.Inferiorly Explanation The nerve fiber layer is thickest at the inferior and superior regions of the nerve, respectively. The inferior and superior arcades are composed of large diameter axons with little overlap of the receptive fields, thus explaining why a field defect occurs in these regions first for early cases of glaucoma. Inferior or superior notching of the nerve is highly suspect for glaucomatous damage, and must undergo further testing in order to rule out glaucoma. The next thickest area of nerve fiber layer tissue is nasally, which is comprised of the nasal radial fibers. These axons are affected in the later stages of glaucoma, thus explaining why a temporal island of the visual field is often left remaining in advanced cases of glaucoma. Lastly, the temporal rim area is the thinnest. Temporal rim tissue is comprised of the papillomacular bundle. The fibers in this area are very small and compact, with a high degree of receptive field overlap, therefore because of the receptive field redundancy, a visual field defect correlating to this region will occur only after significant fiber loss has occurred. Due to the fact that these fibers are so small in diameter, even though they are numerous, the fibers do not occupy a lot of space in the optic nerve. The thickness of the nerve fiber layer rim tissue is best remembered as ISNT, with inferior being the thickest and temporal rim tissue being the thinnest.
A 12-year old male is sitting in your waiting room while his mother undergoes her annual eye exam. While waiting, he eats a candy bar containing peanuts, and, as luck would have it, he is deathly allergic to nuts. To counter anaphylactic shock, what would be the BEST course of action? A.Administration of Benadryl (oral) B.Olopatadine (Patanol) C.Prednisone (oral) D.Injection of epinephrine (EpiPen)
D.Injection of epinephrine (EpiPen) Explanation Anaphylactic shock is defined as a severe, multi-system, type I hypersensitive, acute allergic reaction that may be life-threatening. Signs of an allergic reaction include tingling, itching, hives, swelling of lips and tongue, constriction of the airway, vasodilation, myocardial depression, and a decrease in blood pressure. The EpiPen is injected intramuscularly to the upper lateral thigh to ensure rapid delivery. Epinephrine (Adrenaline) activates both alpha and beta adrenergic receptors causing an increase in peripheral vascular resistance and allowing for an increase in blood pressure and coronary artery perfusion. Adrenaline also serves to reverse vasodilation and decrease urticaria and angioedema. For severe, life-threatening reactions, Benadryl (diphenhydramine) will not work quickly enough. Topical antihistamines have little if any systemic absorption and therefore will not be effective in counteracting the anaphylaxis. While oral steroids may be useful in the post-management of anaphylactic shock, they will not yield the desired immediate response.
A 31-year old male patient presents to your office for a photorefractive keratectomy (PRK) pre-operative examination. As you review his required ocular medication schedule, which of the following prescribed drops must you remember to tell him to "shake well" before instillation? A.Acular® B.Zymaxid® C.FreshKote® D.Pred Forte®
D.Pred Forte® Explanation Pred Forte® is an ocular medication that is in suspension form; therefore, it is important to shake this medication well before use. Other forms of prednisolone that are suspensions include Pred Mild®, Econopred®, and Econopred Plus®. On the other hand, there are prednisolone ocular medications that are solutions, making shaking of the bottle unnecessary. These include AK-Pred®, Inflamase Mild®, and Inflamase Forte®. Zymaxid® is a 4th generation fluoroquinolone antibiotic that is bottled in solution form, as well as Acular®, which is an ocular non-steroidal anti-inflammatory drug (NSAID). FreshKote® is a prescription artificial tear that also does not need to be shaken before use.
Which of the following types of scleritis presents without ocular inflammation, has a low risk for perforation, and does not typically result in pain or decreased visual acuity? A.Posterior scleritis B.Granulomatous necrotizing scleritis C.Anterior non-necrotizing diffuse scleritis D.Scleromalacia perforans E.Vaso-occlusive necrotizing scleritis F.Nodular scleritis
D.Scleromalacia perforans Explanation Scleromalacia perforans is a type of necrotizing scleritis that typically presents without vascular congestion or pain. Clinical observations commonly include yellow-colored necrotic plaques that occur near the limbus without inflammation and very slow progression of scleral thinning that eventually exposes the underlying uveal tissue. Patients commonly complain of a mild non-specific irritation but no pain. Visual acuity is also not usually affected in these patients. Scleromalacia perforans typically affects elderly women with a long-standing history of rheumatoid arthritis. By the time patients are correctly diagnosed with this condition, treatment is usually not needed or is ineffective. Even though the name contains the word "perforans," the risk of perforation is extremely rare, as the integrity of the globe is usually well maintained.
Where do DNA/RNA viruses replicate?
DNA - in the nucleus RNA - in cytoplasm
Grave's signs
Dalrymple = Stare, lid retraction in primary gaze Kocher = Globe lag in upgaze Von graefe = Upper lid lag on down gaze Stellwag's = Infrequent or incomplete blinking Boston's = Spasmadic lowering of upper lid on down Rosenbach's = Tremor of lids when closed
First initial ocular sign of acoustic neuroma?
Decreased corneal sensitivity
How is the temporal modulation transfer function expected to change in a person with early glaucoma not yet manifesting any defects on visual field testing?
Decreased sensitivity to moderate and high temporal frequencies
How is the temporal modulation transfer function expected to change in a person with early glaucoma not yet manifesting any defects on visual field testing?
Decreased sensitivity to moderate and high temporal frequencies due to damage to magnocellular pathway
An 81-year old female reports that her eye has been watering more frequently over the past month; you decide to administer the primary Jones dye test (Jones I). After 5 minutes, the application of a cotton-tipped applicator to the inferior turbinate reveals the presence of dye in the area. Taking this into consideration, what is the MOST likely cause of the patient's epiphora complaint? A. Complete nasolacrimal duct obstruction B. Punctal stenosis C. Dysfunction of the valve of Hasner D. Partial nasolacrimal duct obstruction E. Hypersecretion of tears
E. Hypersecretion of tears Explanation The primary Jones dye test can be utilized to determine the patency of the nasolacrimal system. 1-2 drops of fluorescein are instilled into the inferior fornix of the eyes while the patient is in an upright position and blinking her eyes normally. After a period of 5 to 10 minutes, a cotton-tipped applicator is used to swab the undersurface of the inferior turbinate on each side of the nasal passage. When the primary Jones dye test is positive (dye is recovered from the inferior turbinate of the nose), practitioners may conclude that the system is patent and that no significant blockage of the nasolacrimal drainage structure is likely. However, minor stenosis or physiologic dysfunctions cannot be completely ruled out. Patients who have a positive result on the Jones I test are more likely to experience symptoms of epiphora that are secondary to primary oversecretion of tears, rather than a dysfunction in lacrimal drainage (as in the above question). When the primary Jones dye test is negative, the probability of an obstruction or dysfunction in lacrimal drainage is much greater; however, this test alone is not sufficient to document this conclusion. The secondary Jones dye test is then necessary to determine the severity and location of the obstruction.
A person can just barely detect the difference between two weights; one weighs 12 pounds and the other weighs 10 pounds. What is the just noticeable difference for a weight of 70 pounds? A.2 pounds B.56 pounds C.20 pounds D.8 pounds E.14 pounds
E.14 pounds Explanation Weber's Law deals with the just noticeable difference and can be expressed mathematically as: K= delta I/I, where K= Weber's constant, delta I= that difference threshold, and I= the original stimulus intensity (weight etc.) For the above example, we must first solve for Weber's constant. 12-10/10=0.2. Using this Weber's constant we can then solve for the just noticeable difference or the increment threshold for 70 pounds. X-70/70=0.2, X= 14 pounds. Therefore, the above person will just be able to discern the difference between a 70-pound weight and an 84-pound weight.
What separation distance will make the combination of a +3.00 and a +10.00 thin lens afocal? A.1.7 cm B.23 cm C.2.3 cm D.17 cm E.43 cm F.0.43 cm
E.43 cm Explanation For this question, the equation for equivalent power of a thick lens system should be used, solving for thickness (t). De = D1 + D2 - (t/n) x D1D2 De = equivalent power, D1 = front surface power, D2 = back surface power t = thickness of lens system, n = index between the 2 surfaces An afocal system has its focal points (F and F') located at infinity. Therefore, an incident parallel pencil of light rays will emerge into image space as a parallel pencil as well. Another way to characterize an afocal system is that the equivalent power (De) is 0. In the above question, De = 0, D1 = +3.00, D2 = +10.00, n= 1 0 = 3 + 10 - ((t/1) x (3) x (10)) 0 = 13 - (t x 3 x 10) 0 = 13 -30t 30t = 13 t = 0.43 m (or 43 cm) If the two lenses are separated by 43 cm, the lens system can be considered afocal. This type of combination of two plus lenses is also an example of a simple astronomical (Keplerian) telescope. Keep in mind that the image in this type of optical system is inverted.
A person who is missing the photopigment chlorolabe is categorized as which of the following? A.A protanomalous trichromat B.A deuteranomalous trichromat C.A protanope D.A tritanope E.A deuteranope
E.A deuteranope Explanation There are several classifications of color-vision defects; hereditary defects are the most common. The two broad categories are dichromacy and anomalous trichromacy. In dichromacy, one of the photopigments is missing; the type of dichromacy is categorized based on which photopigment is lacking. A deuteranope is missing chlorolabe, a tritanope is missing cyanolabe, and a protanope is missing erythrolabe. It is theorized that the missing photopigment is replaced by the photopigments that are present; otherwise, the person would likely suffer a deficit in visual acuity. Anomalous trichromats are in possession of all three photopigments but the absorption spectrum of one of the pigments has been shifted. For a protanomalous trichromat, the spectrum for erythrolabe is shifted towards the shorter wavelengths. A deuteranomalous trichromat displays a shift of the maximum sensitivity of chlorolabe towards the longer wavelengths. Protans and deutans are said to be red-green colorblind while tritans tend to mix up blues and yellows and are said to possess a blue-yellow defect; this is usually acquired rather than hereditary.
Which patient would be considered legally blind? A.A patient with a total retinal detachment of the right eye, no light perception and a best corrected central acuity of 8/60 due to wet macular degeneration B.A myopic patient with acuities of 20/400 OD and OS uncorrected C.A patient with Best's disease with best corrected central acuities measure OD 10/80 and OS 10/100 D.A retinitis pigmentosa patient who has 20/20 central vision in each eye and a 30 degree in diameter visual field E.A wet macular degeneration patient with best central acuities of 10/120 OD and 10/200 OS
E.A wet macular degeneration patient with best central acuities of 10/120 OD and 10/200 OS Explanation Legal blindness must take into account central best corrected visual acuity, with the better eye 20/200 or worse. If the central acuity is normal such as in the RP patient then the field would be the restricting qualification, which, at 30 degrees, does not qualify.
What are the following examination findings that indicate the presence of a bilateral fourth nerve palsy?
Extraocular muscle evaluation will reveal a *right hypertropia in left gaze* (due to right inferior oblique overaction), and *left hypertropia in right gaze* (due to left inferior oblique overaction) in cases of bilateral involvement On double Maddox rod testing, the amount of rotation of one Maddox rod (indicating the amount of cyclodeviation) will be less than 10 degrees in unilateral cases and greater than 10 degrees (sometimes even greater than 20) in bilateral cases A cover test performed in different positions of gaze will reveal a *"V" pattern esotropia* in bilateral fourth nerve palsies
Unilateral INO
Eye with limited adduction denotes the affected eye
A 24-year old female patient presents at your office complaining of side effects that began when she started using Patanol® to treat her ocular allergies. She reports complete compliance with her eye drop administration. Which of the following symptoms is MOST likely associated with olopatadine (Patanol®) use? A.Gastrointestinal discomfort B.Depression C.Tachycardia D.Visual Hallucinations E.Headache
E.Headache Explanation Topical antihistamines and mast cell stabilizers such as Patanol® (olopatadine) are commonly prescribed to relieve the symptoms associated with ocular allergies. They are a very effective class of medication due to their dual action mechanisms. Topical antihistamines that possess this dual action are olopatadine (Patanol®), ketotifen fumarate (Zaditor®), azelastine (Optivar®), and epinastine (Elestat®). The aforementioned drops serve to alleviate itching and redness by blocking H1 receptors as well as inhibiting mast cell and basophil degranulation. Side effects of topical antihistamine/mast cell stabilizers include stinging upon instillation, headaches, and adverse taste (don't forget to inform your patients about punctual occlusion!). Tachycardia, depression, gastrointestinal discomfort, and visual hallucinations have not been reported with Patanol® use.
Which type of light scattering is responsible for the reddish-orange colors that are often observed during sunsets? A.Tyndall scattering B.Mie scattering C.Raman scattering D.Brillouin scattering E.Rayleigh scattering
E.Rayleigh scattering Explanation Scattering of light occurs when the medium through which light or other electromagnetic radiation travels is not homogenous. In the case of Rayleigh scattering, the particles that scatter the light are smaller than the wavelength of the light passing through. The particles may be individual atoms or molecules of a solid, liquid, or most commonly, a gas. The appearance of the blue sky during the day and the reddish hue of the sunset are due to Rayleigh scattering of light.
what problems can occur in corneal epi in response to hypoxia? stroma? endo?
EPI: erosions, edema, microcysts, ulceration, vascularization, and a decrease in cellular mitosis STROMA: edema, infiltrates, and vascularization ENDO: guttata, blebs, folds, and/or polymegathism
Your patient likes the stand magnifier you prescribed, but he wants a larger field of view when using the device while maintaining the same amount of magnification. Keeping this same device, which of the following will allow him to achieve a larger field of view?
Explanation - Holding the stand magnifier and reading material at the spectacle plane increases the field of view. Adding OTC reading glasses may lessen the strain on his eyes and increase the overall power of the optical system but does not increase the field of view. A reading add is generally used with stand magnifiers; however, this patient is young and can still accommodate without a reading add.
An increased rate of molecular movement down its respective concentration gradient via help from carrier proteins refers to which type of transportation?
Facilitated diffusion is described as the net movement of molecules down its concentration gradient whose rate of diffusion is increased via the use of carrier proteins. Passive diffusion refers to the movement of molecules through a plasma membrane from an area of high concentration to an area of low concentration without the use of carrier molecules. Active transport implies the movement of material against its respective concentration gradient. This type of transport requires energy and enlists the use of specific carrier proteins. Lastly, group translocation is defined as the chemical modification of a molecule while it is being transported into a cell; for example, sugars are often phosphorylated during transportation.
Dietary triglycerides are metabolized primarily by which organ of the body?
Fat is digested primary in the intestine. -- It enters the intestine from the stomach, where it becomes emulsified by bile salts and hydrolyzed by lipases released from the pancreas. These end products are then absorbed by enterocytes that line the walls of the intestine. Once in the enterocytes, triglycerides are then rebuilt and packaged along with cholesterol and protein to form chylomicrons. Triglycerides cannot directly diffuse through the cell membranes of the liver or adipose tissue; they must first be broken down into fatty acids and glycerol. This process is made possible by lipoprotein lipases located on the walls of blood vessels. The fatty acids and glycerol are then absorbed by the liver for energy or taken up by adipose tissue and re-synthesized into triglycerides for storage purposes.
Greatest risk for DES from LASIK occurs in
Females Patients > 50 YO Hyperopes High refractive errors Asians Patients on medication that causes dryness
Risk factors for dry eye post-LASIK?
Females, 50+yo, hyperopes, higher refractive errors, Asians and patients on medicines that cause dryness.
Worth-4-dot test is considered a test of which type of fusion?
First-degree fusion is the ability to superimpose two dissimilar objects (for example, a circle and a square) such that the two objects are perceived to occupy the same space and appear as an amalgamation of both objects. second-degree fusion, which is the ability to superimpose like objects (not necessarily identical objects), with the end result being the perception of a single object that is a composition of the two separate images. In this test, one eye is presented with a red dot, and the fellow eye is presented with 2 green dots. Both eyes view a white dot. If fusion is present, the patient will report having a binocular percept of 4 dots. Third-degree fusion is described as the ability to fuse two identical images that are separated by space, resulting in the perception of depth. 3-D movies are an example of this type of fusion. The images must be placed at points that cause retinal disparity in order for the perception of depth to ensue.
What does the + on a progressive lens stand for?
Fitting cross - used to measure the fitting height; should go through the pt's pupil
Superior staining of the cornea is suggestive of what?
Floppy eyelid syndrome, superior limbic keratoconjunctivitis, or limbal stem cell deficiency, among other causes.
According to the American National Standards Institute (ANSI), what marking must be seen on the frame in order for it to qualify as a safety frame?
Frames that have successfully met the requirements for high-impact and high mass-velocity tests are marked with Z87-2. Lenses that have passed the high-impact test will have a '+' mark (along with the manufacturer's trademark) permanently etched onto the lens. The letter 'V' symbolizes that the safety lens is photochromic. The letter 'S' denotes that the lens is designated for a special purpose, such as a didymium lens commonly worn by glass-blowers.
What are risk factors for Chronic obstructive pulmonary disease (COPD)
Frequent childhood infections Alpha-1 antitrypsin deficiency Low birth weight
Which of the following systemic conditions are most commonly associated with a central retinal artery occlusion (CRAO)? A) Diabetes B) Hypertension C) Carotid Artery Disease
HTN (75%) usually a heart or carotid embolus. ALSO the most common for CRVO.
why can't hydroxyamphetamine dilate a postG horners pupil
HXA releases NE from postG neurons postG damage means no NE release. preG damage leaves postG neuron intact => NE release, dilation.
Spatial summation displayed by certain photoreceptors of the retina results in which of the following properties? High sensitivity and high resolution Poor sensitivity and high resolution High sensitivity and poor resolution Poor sensitivity and poor resolution
High sensitivity and poor resolution [Spatial summation is used by the scotopic system]
Granular dystrophy type 2
Hyaline deposits in stroma
Development of the eye is coordinated by the neural ectoderm and mesoderm. The embryonic fetal fissure is the last structure to close to allow for the development of what? Hyaloid artery plexus Ciliary body Optic nerve Lens
Hyaloid artery plexus
Embryonic fetal fissure is the last structure to close to allow for the development of
Hyaloid artery plexus
Drugs that can cause pseudotumor cerebri
ICAANT Isotretinoin (accutane) Contraceptives Amiodarone Vitamin A Nalidixic acid Tetracyclines
most common schisis location
IT (70%)
ANSI standard for high impact resistance glasses?
If poly - 2.0mm thick (3.0mm thick if otherwise) Pass high-vel impact test
Which of the following appears to be a risk factor for the development of pseudoexfoliation glaucoma? Increased coffee consumption Warm weather with minimal sun exposure Decreased homocysteine levels Habitation in the southern latitude
Increased coffee consumption
Fatty acid synthesis is activated during which of the following situations?
Increased levels of citrate and insulin, decreased levels of glucagon -- Fatty acid synthesis occurs in cytosol w/ ATP and NADPH. It stimulated by insulin and inhibited by glucagon and epinephrine. The formation of fatty acids is catalyzed via the enzyme acetyl CoA reductase, which is activated by citrate. Citrate comes from acetyl CoA and OAA in mitochondria.
Plus vs Minus lenticular design for contact lenses
Increasing minus power of a gas-permeable lens results in an increased edge thickness and a decreased center thickness. Ordering a plus lenticular design will minimize edge thickness and overall mass of the lens while optimizing lens centration. Lenses that are greater than -5.00 D in power should be ordered with a plus lenticular design. Some authors have suggested that minus lenticular designs should be reserved for all plus-powered gas-permeable lenses or lenses that are less than -1.50 D.
A healthy retinal nerve fiber layer is thickest at which portion of the optic nerve head? Nasally Temporally Superiorly Inferiorly
Inferiorly The nerve fiber layer is thickest at the inferior and superior regions of the nerve, respectively. The inferior and superior arcades are composed of large diameter axons with little overlap of the receptive fields, thus explaining why a field defect occurs in these regions first for early cases of glaucoma. Inferior or superior notching of the nerve is highly suspect for glaucomatous damage, and must undergo further testing in order to rule out glaucoma. The next thickest area of nerve fiber layer tissue is nasally, which is comprised of the nasal radial fibers. These axons are affected in the later stages of glaucoma, thus explaining why a temporal island of the visual field is often left remaining in advanced cases of glaucoma. Lastly, the temporal rim area is the thinnest. Temporal rim tissue is comprised of the papillomacular bundle. The fibers in this area are very small and compact, with a high degree of receptive field overlap, therefore because of the receptive field redundancy, a visual field defect correlating to this region will occur only after significant fiber loss has occurred. Due to the fact that these fibers are so small in diameter, even though they are numerous, the fibers do not occupy a lot of space in the optic nerve. The thickness of the nerve fiber layer rim tissue is best remembered as ISNT, with inferior being the thickest and temporal rim tissue being the thinnest.
Illumination is one of the most important considerations to discuss in the case disposition for a visually impaired patient. A patient with chronic open angle glaucoma moves a 60 watt bulb on a flexible mounted arm from three feet to one foot from the page. The illumination on the page will appear to have been increased by how much? A. Should be the same brightness B. Increased by 9 times the original brightness C. Increased by 3 times the original brightness D. Decreased by 1/9 of the original brightness E. Decreased by 1/3 of the original brightness
It has been said that prescribed optical devices without consideration of the appropriate lighting will often doom the patient to failure. Unfortunately, there are no good tests to determine the exact type of lighting. Generally, different light levels are tried during the examination (as well as during the training session) with the patient using an adjustable light. The distance from the page is very important because of the inverse-square law of illumination: the intensity varies inversely as the square of the distance from the page. If the light is moved from 1 foot to 3 feet from the page, a bulb will be needed that is approximately nine times as bright to keep the same illumination on the page. (It should be noted that technically, this relationship is only true for a point source of light.) Clinically, however, it gives a good approximation of the change in brightness (illumination) seen on the page when the distance of the light is changed. The illumination in the above example would therefore increase by 9X when the bulb is moved towards the page.
•Harmonious anomalous correspondence is a sub-category of anomalous correspondence
It occurs when the sensory adaptation completely compensates for the angle of strabismus o It is called "harmonious" because the angle of anomaly is equal to (in harmony with) the objective angle of strabismus o In these cases, there is no subjective angle of strabismus that can be measured on a cover test •The above patient does have some sensory fusion, indicating anomalous correspondence. He also does not show movement on cover test, indicating that the type of anomalous correspondence is harmonious.
What is example of Vernier acuity clinically
Keratometry
Location of processes within the mitochondria?
Krebs (TCA/citric acid) - in matrix ETC - inner membrane
All of the amino acids that are found naturally in proteins are of which configuration?
L amino acids
axenfelds loops = which nerve
LPCNs represent an anastomosis of a LCN that turns to enter the sclera before looping back again to continue its insertion at CB
The patient wishes to know if the lenses in his current glasses are warped. Which ophthalmic instrument will provide the MOST ACCURATE method of assessing for lens warpage?
Lens clocks are useful instruments that can be used to calculate the base curve of an ophthalmic spectacle lens, determine the add power of a multifocal lens, test for potential lens warpage, determine the amount of slab-off prism on an ophthalmic lens, calculate the thickness of a gas-permeable lens, as well as determine the nominal (or approximate) power of an ophthalmic lens. To test for lens warpage, place the lens clock perpendicular to the lens surface at the geometrical center of the lens and rotate the lens clock. The power reading should remain unchanged. If the power varies, then the lens may be warped or the lens may be a plus cylinder lens. If the latter is the case, then the backside of the lens should be spherical.
Gas-permeable lenses, by nature of design and lid apposition when blinking, tend to rotate 10 to 15 degrees nasally, but not always
Lens rotation must be taken into consideration when ordering a lens from the laboratory for the patient. Allow for 10-15 degrees temporal rotation
Wilson's
Liver, copper deposits, Kayser-Fleischer ring (encircle the periphery of the cornea more prominent vertically.)
Pacinian corpuscles
Located deeper in the dermis than other sensory receptors, sensitive to rapid pressure changes related to vibrations and touch. Also found in some internal organs and in membranes that lie in close proximity to freely-movable joints.
Which 3 of the following signs are the GREATEST risk factors for the transformation of a choroidal nevus to a malignant choroidal melanoma? (Select 3)
Location in posterior pole Orange pigmentation = Observable retinal pigmentation (tumor thickness greater than 2mm, subretinal fluid, orange pigmentation, proximity to the optic disc, and the presence of symptoms.)
what causes peripheral corneal ulceration with unique overhanging edge on the corneal defect
Mooren's ulcer elderly "MORE severe, in pts with MORE years" by definition, no systemic assoc (many conditions can cause periph ulcers in older pts like RA, but then it is NOT called Moorens)
Patient with a low AC/A ratio, how would you expect the phoria to change as the target is brought closer to the patient
More exo or less eso
name for most superficial portion of orbicularis
Muscle of Riolan keeps lid margin tightly apposed to globe during eye mvmts muscle is aka the Gray Line lashes arise anterior to it, MGs are posterior to it
Composition of mutton fat KPs, non-granulomatous KPs
Mutton fat - epithelioid cells, macroph Non-gran KP - neutrophils, lymphocytes
What does the rhombencephalon form?
Myelencephalon --> medulla oblongata Metencephalon --> pons, cerebellum
A patient views a bichrome visual acuity chart with no lenses before his eyes. With the patient's left eye occluded, he reports that the letters on the red side of the chart appear blacker and darker. With his right eye occluded, the letters on the green side appear blacker and darker. Given these observations and assuming that accommodation is at rest, what would likely be the refractive condition of the right eye and left eye respectively? Myopia and myopia Myopia and emmetropia Myopia and hyperopia Hyperopia and emmetropia Emmetropia and hyperopia Hyperopia and myopia
Myopia and hyperopia For an emmetropic eye that is not accommodating, the chromatic interval within the eye would be positioned so that the anterior (green) and posterior (red) ends of the interval are equidistance from the retina (i.e. the midpoint of the interval would be at the retina) and thus the letters on the red and green sides of the chart would appear equally black and dark. For uncorrected myopia, the interval would shift forward and thus the red end of the interval moves closer to the retina. In this case, the letters on the red side would appear blacker and darker. For uncorrected hyperopia, the interval would shift backward and thus the green end of the interval moves closer to the retina. In this case, the letters on the green side would appear blacker and darker.
Lab test to run to dx chlamydia?
NAAT - nucleic acid amplification tests
How does anophthalmos happen? (during development)
Optic vesicle fails to form as an outgrowth of the wall of the diencephalon or optic vesicle does not reach the surface ectoderm due to interference with closure of the neural tube during expansion of the optic vesicle
First pass metabolism
Oral and rectal
What r/adm results in first pass metabolism?
Oral, rectal adm
Eyelid closure
Orbicularis oculi (palpebral for spontaneous and orbital of forced.) Corrugator (corners down and medial, frowning, creates wrinkles) and procerus (area between the eyes down) are also involved. All innervated by CN VII.
Association fibers to the zonules?
Orbiculociliary division - arises from the pars plana, connects to the ciliary processes. Interciliary fibers - run between the ciliary processes and connect the processes to each other Circular fibers - run between the zonules, serving to connect them in a circular pattern like a spider web
VKC
Other allergies, summer and spring, superior cobblestone papillae over 1 mm, ropy discharge that is worse in the morning. Can get shield ulcer and trantas dots
Between which areas of the retina does fluid accumulate in a patient diagnosed with cystoid macular edema (CME)
Outer plexiform layer and inner nuclear layer
Where does phototransduction happen?
Outer seg
Grey matter
Outside of brain and inside of spinal cord. Cell bodies, dendrites and glial cells (interneurons.)
ILM of elschnig
Over the nerve, made by astrocytes
EKG breakdown
P = Atrial depolarization Q = Depolarization of intraventricular septum S = Depolarization of base of ventricles T = Ventricular repolarization PR interval = From P to Q No peak for atrial depolarization
ECG waves
P wave: contraction of the atria QRS complex: contraction/depolarization of the left and right ventricles T wave: relaxation of the ventricles
mnemonic for angioid streaks
PEPSI Pseudoxanthoma Ehlers danlos Pagets Sickle cell Idiopathic
ELM separates what
PR inner segments from their nuclei
What layer of the cornea is the laser applied during PRK, LASIK?
PRK = Bowmans Lasik = midstroma
list ALL RP signs
PSCs macular changes (CME, ERMs, atrophy) attenuation, bone spicules, waxy disc pallor
Which of the following is the MOST common early pattern of a glaucomatous visual field defect? Para-central scotoma Superior arcuate Inferior arcuate Superior nasal step Enlarged blind spot Inferior nasal step
Para-central scotoma Characteristic defects in glaucoma consist of damage to the optic nerve head, resulting in a retinal nerve fiber bundle defect. The configuration of nerve fibers served by the damaged bundle will correspond to a specific defect in the visual field. The earliest visual field changes that may suggest glaucomatous damage commonly consist of an increased variability of responses in an area that will eventually develop a defect. When a glaucomatous visual field defect does occur, it tends to initially present as a paracentral scotoma. Paracentral scotomas are typically small and relatively steep depressions that are most commonly observed just supero-nasal to the fovea. Approximately 70% of all early glaucomatous field defects can be characterized as a paracentral scotoma. This type of defect is due to damage of the papillomacular bundle which will respect the horizontal midline. It is important to remember that a single visual field test cannot definitively prove that a visual field defect exists. For this reason, interpretation of visual fields should not be performed in isolation, but rather in conjunction with other clinical findings (IOP, appearance of optic nerve, RNFL). According to Kanski's Clinical Ophthalmology, there is a set of minimal criteria for determining glaucomatous damage (also known as Anderson's criteria), which is summarized below: 1. Glaucoma hemifield test that is "outside normal limits" on at least 2 consecutive occasions. 2. A cluster of 3 or more non-edge points in a location typical for glaucoma, all of which are depressed on pattern standard deviation (PSD) at a P < 5% level and one of which is depressed at a P <1% level, on 2 consecutive occasions. 3. Corrected pattern standard deviation (CPSD) that occurs in less than 5% of normal individuals on two consecutive fields.
How does the autonomic system influence insulin/glucagon levels?
Parasymp --> more insulin in blood Symp --> more glucagon in blood
WHAT 2 hormones are key in Ca homeostasis
Parathyroid hormone increases blood Ca (stimulates clasts) calcitonin gets rid of blood Ca (inhibits clasts + Ca/phos resorp)
Atheromatosis
Plaque depositing on the inner wall of the blood vessel leading to damage to that vessel
A four-month old infant female presents at your office. Her mother reports red, mildly swollen eyes with mucopurulent discharge, with the eyes having been sealed shut in the morning over the previous two days; the condition first presented in the right eye. Which of the following medications is FDA-approved in infants to treat her conjunctivitis? Ciloxan® (ciprofloxacin) Vigamox® (moxifloxacin) Polytrim® (trimethoprim / polymixin B) Gentamicin
Polytrim® (trimethoprim / polymixin B)
Photopic system
Poor resolution but good summation
Magno
Poor spatial resolution and good temporal resolution
An oblate shaped cornea is one in which the corneal curvature is flattened in the center and then steepens in the periphery. Which is associated with
Post LASIK myopes Post orthokeratology Post radial keratotomy
A 66 year-old male presents with a facial nerve palsy resulting in weakness of both the upper and lower portions of the right side of his face. Which of the following BEST describes the characteristics of the involved motor neuron? Right lower motor neuron Left lower motor neuron Left upper motor neuron Right upper motor neuron
Right lower motor neuron A unilateral lesion to a lower motor neuron of the facial nerve will result in weakness of upper and lower portions of the face on the ipsilateral side of the lesion. Therefore, in this case, because the upper and lower portions of the right side of the face are affected, the involved motor neuron would be a right lower motor neuron. The branch of the facial nerve that serves the upper portion of the face receives innervation from both the right and left corticobulbar tracts, while the branch of the facial nerve that serves the lower portion of the face only receives innervation from the contralateral side of the brain. If a lower motor neuron lesion occurs, both of these branches are affected, and all muscles of facial expressions beyond that point on the ipsilateral side of the face will experience weakness.
what nerves pass thru SOF? IOF? where is IOF/what bones?
SOF = 4 CNs (3-6) IOF = V2 IOF is formed @ apex of orbit by maxillary, zygomatic & greater wing
vision loss from AION is from lack of flow to which artery: LPCA SPCA anterior cerebral superficial temporal
SPCA (Circle of Zinn - blood to anterior surface of optic disc) inflam of superficial temporal artery isn't responsible for vision loss bc it has no role in blood supply to ON
what supplies blood to macula, optic disc + PP/majority of choroid
SPCAs
Weakness of which EOM is MOST commonly associated with a simple congenital eyelid ptosis?
SR (levator & SR nuclei are close together)
whats responsible for the pain on eye mvmts that occurs in 90% of optic neuritis
SR and MR share common sheath with intraorbital ON
Fluoxetine is a
SSRI NO anti-cholinergic activity
most common quadrant for BRVO? why?
ST quadrant bc edema is more likely to leak into macula => Sx => pt comes in. otherwise BRVOs don't get diagnosed bc no Sx.
how to find near point using the formula Ffp = -STA + Fa
STA = amplitude Fa = near point vergence 1/Fa = near point in mm
A dilated fundus exam reveals white crystalline deposits within the macular region of your patient. Which of the following medications is MOST likely responsible for causing these deposits? Tamoxifen Ciprofloxacin Plaquenil® Amiodarone
Tamoxifen
List all the AE of acetazolamide
TRANSIENT MYOPIA metabolic acidosis weight loss decreased libido depression, malaise paresthesia (numb/tingling) metalliic taste hypokalemia kidney stones blood dyscrasias (Ae. aplastic anemia) dermatitis (contraindicated in pts with sulfa allergies)
pituitary makes what 7 hormones
TSH, GH, ACTH FSH, LH, prolactin melanocyte-stimulating
Salt pan
Talcum powder prevents pitting of the frame
Which portion of a nephron is NEVER permeable to water? The ascending limb of the loop of Henle The descending limb of the loop of Henle The glomerular apparatus The proximal tubule The distal tubule
The ascending limb of the loop of Henle
The Goldmann 3-mirror lens is comprised of a central Hruby lens
The central lens is a 64 diopter lens that is used for viewing of the posterior pole (also known as the Hruby lens). The smallest mirror is the bullet (or thumbnail) shaped mirror, which is used for examination of anterior chamber structures (angles), as well as the ora serrata due to the angle that the mirror is positioned (59 degrees). The middle-sized lens is square-shaped and has a different angle of orientation (67 degrees), permitting the observation of the retina anterior to the equator or the peripheral retina. Lastly, the larger trapezoidal-shaped mirror is oriented such that it allows for viewing of the retina between the equator and the macula (73 degrees). Because these are mirrors, the location of the area that is examined is 180 degrees opposite from the position of the mirror.
The lens changes significantly as we age. One of these changes is the formation of vacuoles. What causes this? Loss of lenticular capsule elasticity causing decreased accommodation Glutathione loss with age causing cross linking between proteins Decreased function of the sodium/potassium pump causing decreased protein synthesis The separation of water from proteins causing agglutination of proteins and pooling of water
The separation of water from proteins causing agglutination of proteins and pooling of water Crystalline proteins are normally water-soluble. With age, they begin to clump together altering the amount of water that they are capable of binding to. The water begins to pool together creating vacuoles. The pooling of water causes light scattering because the index of refraction differs between that of the lens proteins and the water aggregations. Glutathione loss and decreased function of the ion pump do indeed contribute to cataract formation, but the direct cause of vacuoles is pooling of water. Loss of capsular elasticity leads to presbyopia.
What is the normal positioning of the upper and lower eyelids in comparison to the limbus
The upper lid normally rests about 2 mm lower than the upper limbus and the lower lid rests about 1 mm above the lower limbus
Interferon retinopathy
The use of interferon for the treatment of certain systemic diseases (such as hepatitis C) has been associated with the development of retinopathy. Most commonly, the retinopathy includes hemorrhages and/or cotton wool spots that occur mainly in the area surrounding the optic nerve. These symptoms may present either unilaterally or bilaterally, and have been reported to arise in anywhere from 18% to 86% of patients using interferon therapy (it is thought that the different rates may reflect a dosage effect).
A cornea that displays toricity is said to have with-the-rule astigmatism if it possesses which of the following keratometry readings?
The vertical meridian is steeper than the other principal meridian -- If the steeper meridian lies between 60 and 120 degrees, the cornea is said to have with-the-rule astigmatism. The horizontal meridian is flatter and corresponds with the axis of the astigmatism. If the steeper meridian lies between 150 and 30 degrees, the cornea displays against-the-rule astigmatism. Anything between 30-60 or 120-150 degrees is oblique.
Malus' Law
Tpol = cos^2(theta) Tpol = the amount of transmitted light after it has passed through the polarizer theta = the angle between the incident light and the transmission axis
Transduction
Transfer of bacterial DNA to another via a virus
Job of lipoproteins? Examples?
Transport lipids in the blood Chylomicrons, VLDL, LDL, HDL
UV-A-B-C
UV-A: longest (315-380); least damaging; penetrates deeper layers of skin UV-B: (280-315); sunburn, skin cancer, cataract; UV-C: (100-280); shortest wavelength; highest energy, most absorbed by ozone; solar keratitis - cornea absorbs most UVC ; lens absorbs UVA/B
Which one of the main proteins in the vitreous is comprised of a unique type of collagen?
Vitrosin
Color blindness
X linked recessive. So both chromosomes have to be positive to express the gene. Carrier if they only have 1. A colorblind mom will have 100% of her children be carriers
predominant pigments in macula
Zeaxanthin, lutein and meso zeaxanthin. Anti oxidant and absorb UV rays. These are essential thus they cannot be synthesized by the body and must be taken in the diet. ARMD and RP have low levels of these
AZT is what drug
Zidovudine - nucleoside anaong of thymidine inhibits RNA dependent DNA polymerase
A deficiency in what minerals or vitamins can lead to night blindness
Zinc
A deficiency of which of the following minerals or vitamins can lead to night blindness? Zinc Vitamin K Selenium Copper
Zinc
Different prostaglandins and their MOAs
Zioptan, Travatan, Xalatan - uveoscleral outflow Rescula - trabecular outflow Lumigan - both outflows
2 main etiologies of RCE =
abrasion dystrophies (EBMD mainly)
prazosin MOA
alpha adrenergic ANTagonist
what secretes glucagon
alpha cells of pancreas
where are incisions placed in RK
arcuate incisions on opposite sides of the corneal periphery in the meridian of the "plus" cyl axis => create flattening of steeper curve (w/ some smaller steepening of flat curve) to reduce amt of corneal cyl
where do the following occur: beta oxidation? proteolysis?
beta-oxidation (FA breakdown) = muscles, liver + adipose. Proteolysis = 1* in muscle cells
penicillins & first gen cephs are more effective against what gram
better for gram (+) limited gram (-) ex. keflex, dicloxacillin
ocular dominance: columns 5 and 6
binocular but dominant for ipsi eye (7 = ipsi only)
what causes Hadinger's brush
birefringence of the macula (Henle's layer)
how many endo cells at birth? at age 70? how many leads to edema?
birth: 3,000 mm2 age 70: 2,000 edema: 500 or less
capillary hemangiomas respond to pressure how? tend to change color when?
blanch with pressure tend to change color with Valsalva, crying or straining due to changes in blood flow
compare/contrast bspasm & myokymia
both = orbicularis oculi myokymia = ONLY OO bspasm = oo, procerus + corrugator myo = unilateral twitch bspasm = bilateral twitching that progresses to lid closure Meige syndrome = benign essential bspasm plus lower facial abnormalities (difficulty chewing, opening mouth etc.)
Reyes syndrome is most destructive to which organs? almost always AW what?
brain + liver (but it affects all organs) almost always AW previous viral infection
what are macs called in the brain, liver, blood, lungs, intestine
brain = microglia liver = Kupffer cells Blood = monocytes until cells leave blood, then called a mac Lungs = alveolar cells Intestines = mesentery cells
Apnea
breathing suddenly stops for a brief instant, then resumes
Simbrinza =
brimonidine (a2 ag) + brinzolamide (CAI)
Combigan =
brimonidine (a2 ag) +timolol
when does Vernier hyperacuity reach adult levels
by 6-8 years old (whereas standard spatial acuity is by 3-5 yo)
a symmetric donut of glistening yellow deposits surrounding macula may be caused by
canthaxanthin (carotinoid supp for tanning)
high doses of what may produce bilateral crystalline retinopathy - fine yellow deposits in inner layers?
canthaxanthin (carotinoid supp for tanning) -symmetric donut of glistening yellow deposits surrounding macula
carcinoma = cancer of _ tissue sarcoma =
carcinoma = epi sarcoma = CT
most common cause of amaorusis fugax
carotid disease (any ophthalmic or ciliary artery blockage can cause too) ARTERIAL PROBLEM. MONOCULAR
Nocturnal myopia
change in the accommodative response during periods of low illumination. primarily to increased accommodative response associated with low levels of light. Because there is insufficient contrast for an adequate accommodative stimulus, the eye assumes the intermediate dark focus accommodative position rather than focusing for infinity thus creating myopic refractive error. Lastly, the Purkinje shift is thought to contribute to nocturnal myopia. The Purkinje shift is the switch from photopic vision (mediated by cones) to scotopic vision (rod-based vision). This phenomenon occurs most often in individuals aged 16-25. Symptomology includes a decreased ability to read street signs at night, reduced depth perception, and an increase in perceived glare from oncoming traffic.
Claude syndrome =
combo of both Benedikt (red) + Nothnagel (peduncle/ataxia) syndromes. third + hemitremor + ataxia.
MOA of atropine
competitively inhibits Ach from binding to muscarinic receptors
Polarized lenses
constructed with a vertically-oriented filter, allowing only light parallel to this orientation to pass through the lens, and blocking the transmission of horizontally-positioned light rays.
Fuchs endothelial dystrophy
cornea guttata with stromal edema, bilater, fine pigment dusting on endothelium, central epithelial edema and bullae
how to calculate total induced prism when someone looks 10 mm below center in a FT 25 bifocal with seg drop 4 mm
distance P = 1(F) FT25 OC is 5 mm below seg line seg drop = 4mm so OC = 9 mm below dist OC pt looks 10 mm down => looking 1 mm below seg OC. USE ADD POWER ONLY, NOT NET near P = 0.1(add) NET if both same direction (BD), SUBTRACT 3^ dist - 0.2^near = 2.8^BD
MOA of bromocriptine?
dopamine agonist causes mydriasis
dot/blot hemes are in which layer? cotton wool spots are in which layers?
dot/blot = INL cotton wool = NFL
Complete achromatopsia or rod monochromatism
fairly rare occurrence in which the three types of cone photoreceptors do not function. Because the patient uses only rods to see, it is common to observe a visual acuity of 20/200 or worse, a central scotoma, photophobia, poor or no color discrimination, and eccentric viewing. Patients with this condition frequently manifest pendular nystagmus that may abate with time. The fundus of an achromatopsia patient will appear normal. ERG results will display normal rod functioning but will completely lack a cone response.
what is the tectotegmental tract (aka interneuron loop)
fibers from pretectal nuc to both EW nuclei (the 1/3 of ON fibers that leave before LGN)
what cells are found in CT
firboblasts plasma cells (B cells that make ABs) mast cells (heparin+histamine) Macs Pericytes Fibers = collagen, GAGs
which cells develop first in retina? last?
first = GCs last = Muller GCs then horizontals, cones, amacrine, BP, rods, & Muller.
FLATTENING LENSES IF FIT TOO TIGHTLY=
flatten the base curve, decrease the OAD, decrease the optic zone, flatten the peripheral curve system, and widen the width of the peripheral curves.
Decreasing the optic zone ___ the lens, Increasing the optic zone ____ the lens.
flattens, steepens. Making the OZ larger will steepen the lens, but will also alter the bearing surfaces around the lens.
What drug inhibits NaCl reabsorption from luminal side of epi cells in early DCT
hydrochlorothiazide (inhibits Na/Cl pump) -also decreases Ca excretion bc enhacing passive resorp
(+) catalase means bacteria can breakdown what? examples of catalase + and - bacteri?
hydrogen peroxide POSITIVE: Staph + micrococci NEGATIVE: E. coli + Campylobacter
acute hydrops
in some patients with keratoconus, the cornea will progressively thin to an extent that Descemet's membrane ruptures. When this occurs, there will be a sudden influx of aqueous into the cornea known as acute hydrops. Symptoms of hydrops include a sudden decrease in visual acuity, redness and pain in the involved eye. Slit lamp examination will reveal prominent central or inferior corneal edema, clouding and conjunctival hyperemia. The contralateral eye generally exhibits findings of keratoconus, but without hydrops. Keratoconus is usually asymmetric, meaning that in most cases one eye has a more advanced stage of the disease than the other eye. This condition tends to be self-limiting in approximately 8-10 weeks. Conservative therapy would include 5% sodium chloride drops during the day and 5% sodium chloride ointment at night. Broad-spectrum antibiotics may also be used to protect the potentially compromised cornea from possible secondary infection. Corneal scarring after resolution of the hydrops episode is common, and steroid drops may be used in an effort to minimize resultant scar formation.
(+) macular photostress test indicates
indicates that source of decreased acuity is macular, not optic nerve (bright light 2 cm from eye for 10 seconds, measure how long to read 1 line above BCVA. normal is < 60 sec.)
glycerol phosphate shuttle function
initially transfers NADH in cytosol => series of rxns => FADH2 in mitos to use in ETC shuttle generates 2 ATP
put these muscles in order from superior to inferior in the orbit: SR, SO, levator
levator, SR, SO (most inferior)
which CNs exit from midbrain, pons, medulla
midbrain = 3 + 4 pons = 5 6 7 8 medulla = 9-12 CN 6 exits pons, then courses btwn pons + medulla toward the LR muscle. (CN 6 = only CN to course btwn pons & medulla)
what brain structure is responsible for controlling consciousness
midbrain. uncal herniation can cause coma
what time of day is AQ production LOWEST
midnight to 6 AM AQ production is reduced by up to 50% due to B-arrestin cAMP cascade regulation from b2 receptors this does NOT mean IOP necessarily decreases at night - in fact, night IOP spikes have been reported & may play a role in GL
the avg person has much better _ acuity than resolution+recognition
minimum detectable acuity
what is the power of the tear lens if you Rx a flatter CL (higher bc/radius, lower K)
minus (45 cornea + 44 CL = -1.00 tear lens)
what causes madarosis
missing lashes -scar tissue -pathology like bleph -chemo
when is frontalis active
only in extreme upward gaze
what types of nerves are in corneal epi
open-ended nerve endings (nociceptors)
gram__ bacteria have more peptidoglycan
positive
be afraid of mucormycosis in what ps
pts with orbital cellulitis who have DM or immunocomp life-threatening
when does eye reach its max size
puberty
Optic disc drusen
present in roughly 0.3 % of the general population. Drusen of the optic nerve is generally bilateral; however, it may present unilaterally. Pain is typically absent in this condition, as are headaches and diplopia. Early on in life, the drusen may be located deep beneath the surface of the optic disc, causing it to appear pseudo-papilledematous, except that the disc should not appear hyperemic and surface vessels should remain visible. As time passes, the drusen may become more prominent and move towards the surface of the disc and become exposed, causing the margins of the nerve to appear irregular. It is fairly common to observe an associated field loss. Rarely, a choroidal neovascular membrane may develop adjacent to the nerve. In the presence of elevated intraocular pressure, the clinician may consider treating for glaucoma, because it can be difficult to determine if the field loss is due to glaucoma or the drusen. Discs with drusen will generally not develop the cupping typically observed with glaucomatous damage. Optic disc drusen is seen almost exclusively in Caucasians.
ACE inhibitor suffix
pril
diffuse lamellar keratitis post lasik
referred to as the Sands of Sahara, typically occurs two to five days post-LASIK. Initially, the patient will note a progressive decrease in visual acuity. Biomicroscopy will reveal diffuse inflammatory infiltrates located across the periphery of the surgical interface but not penetrating the stroma nor extending into the flap. Very early cases will display infiltrates along the edge of the flap. Generally, there will be little to no injection of the conjunctiva, the corneal surface will remain intact, and there will be no reaction in the anterior chamber. The patient usually does not notice any discomfort. As the condition progresses, the patient will continue to notice a decrease in acuity. The subjective refraction will become hyperopic with astigmatism. The number of granular infiltrates will increase and diffusely cover the flap interface, and a central haze will develop. With time, the central haze will become more condensed and may appear wave-like. Stromal folds may develop, but some believe that this is actually not related to DLK but some other variant and thus should not be classified as DLK. Either way, treatment is aggressive and consists of topical steroid drops every hour. If the infiltrates are severely condensed, the flap may have to lifted, the interface debrided, and the flap refloated to remove the infiltrates. If this condition is not detected and treated early, stromal melt along with severe scarring and poor visual acuity could ensue.
What is Maxwell's spot
shine purple light on retina --> pt will see a red spot (typically @ the point of fixation) why? bc blue is absorbed by macular pigments (not PRs) can be used to Dx EF.
Tetracycline, when administered to children, can lead to :
short stature due to the fact that tetracycline becomes incorporated into calcifying bone, leading to stunting of growth. Tetracycline also causes yellowing of teeth because it can be integrated into dentin and enamel in developing teeth. Other common side effects of tetracycline include allergic response, photosensitization, and GI distress
where does lipid biosynthesis occur in euk cells
smooth ER (ROUGH ER = protein synth)
where are cytochrome P450 enzymes located? role?
smooth ER within hepatocytes role = metabolizing drugs that are absorbed thru small intestine (first pass metabolism) degradation by P3450 results in low circulating drug conc after oral admin.
pts with ectopia lentis should be screened for what? what test?
sodium nitroprusside test to measure homocysteine in urine
Red eye, several SEI's OU but intact epi, severe meibomian stasis OU. Dx?
staph marginal keratitis (severe meibomian stasis = bleph which is expected in these pts bc staph is culprit)
beaten bronze macula =
stargardts (late)
how does an Adies pupil behave in the light
stays dilated (you'd expect constriction)
what region is most common site of retinal break in pts with rhegametogenous RD
superior temporal (60% of cases) ST, then SN, then IT close to 50% of eyes with an RD will have more than 1 RD, typically within 90* of each other.
pt has irregular cyl + peripheral superior thinning OU + yellow-white stromal infiltrates. Dx?
terriens bilateral males over 50, no Sx starts superior, usually doesn't cause ulceration (mooren's can start superior but progressing to ulcer much more common)
malate-aspartate shuttle function
transport NADH from cytosol to mitochondria NADH produced via glycolysis in cytosol, has to go to mitos to serve in ETC as initial proton /e- donor shuttle yields 3 ATP for every 1 NADH brought to mito.
CARNITINE SHUTTLE function
transport fatty acetyl coAs (fats) thru cytosol to mitos for oxidation
Rimantadine is used to treat
treat + prevent infection by Influenza A (aka Flumadine)
basic unit to measure retinal illumination
trolands
tropias are only present on __ phorias?
tropias = only UCT phorias = only ACT
Absence of an upper eyelid crease is commonly seen in congenital ptosis, whereas a high eyelid crease suggests an aponeurotic ptosis. True or false
true
T/F: Compared to cones, rods have a longer outer segment, more discs, and a higher concentration of photopigments
true
True or false: The optic pit is an isolated finding and the patient's macular area remains unaffected, therefore she may be monitored annually unless symptoms dictate otherwise.
true
t/f: once SEIs are present, an EKC patient is no longer considered contagious
true
t/f: the eyes close 2x as fast as they open
true
T/F: the equatorial circumfrence of the lens decreases during accom
true bc the lens becomes more spherical during accom
T/F: higher plus lenses have steeper front & flatter back.
true (minus = opposite)
T/F: the lens becomes more spherical during accom
true (so the equatorial circumfrence of the lens decreases)
T/F: lattice type 3 is AR
true but all the other lattices are AD
T/F: cones have a larger synaptic terminal than rods
true cone pedicles > rod spherules
T/F: advanced Hodgkins could cause exophthalmost
true could theoretically infiltrate orbit & produce exophthalmos but rare, would be seen late in the course of disease
T/F: gap junctions directly connect cytoplasm btwn 2 cells
true found in heart + other places where swift conduction is essential
T/F: The therapeutic index of a drug is defined as TI=LD50/ED50
true thus the higher the lethal dose & the lower the effective dose, the higher the therapeutic index. high TI = safer
T/F: In the eye, short wavelengths tend to scatter more from small particle scatter (e.g. water vacuoles),
true - blue bends best
T/F: phenylephrine reduces IOP
true!
T/F: dont hold cover too long during UCT
true, bc could result in an underlying phoria being expressed & mistaken for a trope
T/F: aortic valve closes just before the pulmonary valve
true, bc the ejection of blood ends first in the left ventricle
T/F: DLK does not result in corneal epithelial defects and usually does not result in high levels of irregular astigmatism, but can cause slight hyperopic shift.
true. shift bc stromal tissue melts as inflam advances => flattening of cornea => hyper shift
T/F: a high therapeutic index means a drug is safer
true. low TI = more dangerous TI = LD50/ED50 ed= effective dose LD50 should be way way higher than effective dose (high TI) the clinical margin of safety is defined as LD1/ED99 meaning that to have a high margin of safety, there should be a large diff btwn the ratio of the lethal dose to 1% of the population to the ED to 99% of pop.
Anomalous correspondence occurs only under binocular fusion. T or F
true. •If a patient has strabismus, he will typically either see diplopia or suppress the image from the strabismic eye •In cases where the patient is able to fuse the images in each eye (despite strabismus), this would indicate that he must have anomalous correspondence
lasik Rx restrictions
up to: 12.00 myopia 6.00 astig 6.00 hyper (use optical cross to find total myopia)
Moore's lightning streaks are what? caused by?
vertical flashes of light - indicate potential problem in peripheral retina
__ deficiency can lead to night blindness why?
zinc needed to convert retinol to retinal (necessary for preventing oxidation; aids wound healing) less zinc = less retinol dehydrogenase which is needed for vitamin A to function properly
describe lens in homocysteinuria
zonules are very abnormal -lens doesn't accom -up to 1/3 of cases of subluxation completely dislocate into vitreous or AC also risk of thrombosis + occlusions LOOK FOR ECTOPIA LENTIS!
Clinical presentation of microtropia:
•Patients usually present with decreased visual acuity in 1 eye (not fully corrected by refraction) o Uncorrected anisometropia is present in nearly all cases of microtropias, most commonly associated with hyperopia or hyperopic astigmatism •Fundus examination reveals no ocular pathology •Although a central foveal suppression scotoma is typically evident in the affected eye, parafoveolar fixation is a common occurrence o Because of this, patients will usually show reduced stereopsis (rarely absent) o A correlation exists between the angle of deviation and the degree of stereoacuity possible A cover test, cover-uncover test, and alternating cover test should be carried out meticulously in patients suspected of having a microtropia •If patients have central fixation, the alternating cover test will show movement (positive) •In cases of eccentric fixation and anomalous retinal correspondence in which the angle of anomaly is not equal to the degree of the eccentric fixation, the alternating cover test will also be positive o Known as "microtropia without identity" •In cases of eccentric fixation and anomalous retinal correspondence in which the angle of anomaly is equal to the degree of eccentricity, no manifest deviation can be detected as the alternating cover test is negative (no movement) o Known as "microtropia with identity" o This presentation may be difficult to diagnose, but reduced unilateral visual acuity with binocular single vision may rouse suspicion •If the cover test is positive, the diagnosis of a microtropia may be established •If the cover test is negative; further investigation of fixation is necessary o If there is non-foveolar fixation, the diagnosis of microtropia may be confirmed
Fixation disparity curve
•Points to remember with forced vergence fixation disparity curves °The Y-intercept represents fixation disparity •Eso fixation disparity is a positive value (shifted upward) •Exo fixation disparity is a negative value (shifted downward) °The X-intercept represents the associated phoria •Base-out is to the right •Base-in is to the left °The flatter the slope, the better the eyes are able to adapt to vergence demands °A steeper slope indicates poor adaptation In a patient with fusional vergence dysfunction, a plotted fixation disparity curve will typically exhibit a very narrow curve with a small flat zone, indicating poor vergence adaptation and a relatively small zone of clear and single binocular vision.
