NBEO part 1 Optoprep

Which 3 of the following are thought to be risk factors for Chronic obstructive pulmonary disease (COPD)? -An increased production of surfactant -Decreased angiotensin converting enzyme (ACE) levels -Frequent childhood infections -An alpha-1 antitrypsin deficiency -Low birth weight -Overexposure to lead

-Frequent childhood infections -An alpha-1 antitrypsin deficiency -Low birth weight COPD is an irreversible, progressive narrowing of the airways which eventually leads to fibrosis and destruction of alveolar tissue. Symptoms include a cough (with or without sputum), shortness of breath that worsens with activity, wheezing, fatigue and/or difficulty catching one's breath. The biggest risk factor is smoking cigarettes. Other risk factors include: a low birth weight, age, a dusty work environment, decreased levels of alpha-1 antitrypsin levels, damp housing quarters, a diet that is low in fish, fruits and antioxidants, frequent childhood infections, and exposure to environmental pollution. It is also purported that a history of atopy and a hyper-responsive airway (the Dutch hypothesis), as well as persistent bronchopulmonary infections (the British hypothesis) may also increase the risk for COPD. There exists much debate surrounding COPD and its relationship to asthma. Currently it is believed that both conditions lie along opposite ends of a spectrum. While both conditions cause limited airflow, the mechanisms and the permanence of the destruction differs. With COPD, the instigator is typically cigarette smoke, which leads to the release of alveolar macrophages, neutrophils and CD8 T-cells. COPD typically affects the peripheral pulmonary pathways, eventually leading to parenchymal destruction, metaplasia of squamous cells and mucous causing irreversible airflow constriction. COPD does not respond well to steroid therapy. In contrast, asthma involves mast cells, eosinophils, macrophages and CD4 T-cells that become activated by exposure to allergens. Asthma affects the proximal pulmonary pathways leading to bronchoconstriction, fragile epithelial tissue, and mucous metaplasia, causing reversible airflow constriction which responds well to steroid therapy. In the event of severe asthma, there is more overlap between the two conditions, since neutrophils, macrophages, CD4 and CD8 T-cells are involved, which lead to airflow limitations of both proximal and peripheral airways. Severe asthma responds mildly to steroid therapy.

You decide to perform the Schirmer 1 test (without anesthetic) on a 23 year-old patient with symptoms of dry eye. After a period of 5 minutes, which of the following values indicates the threshold whereby any measurement below this is considered abnormal? 25mm 15mm 12mm 10mm 18mm

10mm When the Schirmer test is performed properly, patients with normal tear production will have a total amount of tear secretion that wets at least 10mm of the filter paper after a period of 5 minutes in the eye. Before placing the Schirmer strip in the eye, the eye should be gently dried of any excess tears using a cotton-tipped applicator at the inferior conjunctival fornices on both sides. The filter paper should be folded 5mm from one end and placed in the lower conjunctival sac near the junction of the middle and outer third of the lower eyelid. Care should be taken not to touch the strip to the cornea or eyelashes upon insertion. After 5 minutes, the filter paper should be removed and the amount of paper that is moist is measured from the fold.

You are measuring accommodation on your 8 year-old male patient. He is a 0.75 diopter myope, and is tested outside of the phoropter with no spectacle correction. He notes blur at 8cm with both the right and left eyes. What is his amplitude of accommodation? 12.50 diopters 12.00 diopters 11.75 diopters 13.00 diopters 13.25 diopters

11.75D To determine the amplitude of accommodation for each eye in adults, one eye is occluded while the subjective findings are left in place, and the patient is asked to focus on one or two lines above their visual acuity threshold on the reduced Snellen chart. The chart is brought closer to the patient until they report that the line first becomes blurry. This measurement is repeated with the other eye; the results are then converted from cm to diopters, yielding the near point of accommodation. In younger patients, accommodation testing often cannot be performed in the phoropter because their amplitudes of accommodation are typically greater than 10cm (which is off of the scale of the phoropter rule). If the patient is not corrected with the subjective refractive data, this must be taken into consideration. For example, the above patient reported that the chart became blurry 8cm from his eyes; 1/0.08= 12.5 diopters. Because he is also a 0.75 diopter myope, he is actually accommodating 0.75 diopters less at near; therefore, this must be subtracted from the initial measurement, rendering his true amplitude of accommodation as 11.75 diopters for both the right and left eyes.

You are evaluating the function of the levator muscle in a patient with a suspected myogenic ptosis. A measurement less than what value would be considered abnormal? 6mm 5mm 9mm 12mm

12mm Measuring levator function (upper eyelid excursion) is a very helpful test in aiding in the diagnosis of a ptosis and identifying the underlying etiology. The measurement is achieved by having the patient look down while placing a thumb firmly against the brow to negate the action of the frontalis muscle. The patient is then instructed to look up as far as possible, and the amount of excursion is measured with a ruler. - Average levator function is about 15mm - A value of 12mm or above is considered "good" - "Fair" levator function is 5-11mm - 4mm or less is considered "poor" - Typically anything below 12mm is considered abnormal

What is the average period of time an eyelash of an adult continues to grow? 6 months 2 months 1 month 4 months

2 months Eyelashes grow at a fairly slow rate. A single eyelash grows on average for two months and then falls out after a period of roughly three to five months. Eyelashes tend to grow faster and have a quicker turnover rate in children.

Tear volume in a normal, healthy, young adult measures approximately between which of the following values? 17.0-20.0 microliters 9.0-12.0 13.0-16.0 microliters 2.0-5.0 microliters 6.0-8.0 microliters

6.0-8.0 microliters 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.

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? 24 hours 4-5 days 7-10 days 72 hours 10-12 hours

72 hours Oral acyclovir is the mainstay of therapy for patients diagnosed with herpes zoster ophthalmicus. This systemic treatment is maximally beneficial if 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.

An object is located 50 cm from the corneal plane of an eye with 2.00 D of myopia. What degree of accommodation is required to achieve a clear retinal image of the object with no corrective lens in place? 0.00 D -2.00 D +2.00 D +1.50 D +1.00 D

A 2.00 D myope has a far point of 50 cm (1/2.00 D= 0.50 m or 50.0 cm). Because the object is located at the far point of the eye, no accommodation is required to bring the image into focus.

What is a pneumothorax? A broken rib An embolism of the lung A collapsed lung An inflammation of the pleural membranes

A collapsed lung A pneumothorax occurs when air collects in the space that surrounds the lung. This increases the pressure on the lung and may lead it to collapse. Common causes are chest trauma and lung diseases such as asthma or COPD; however, sometimes a pneumothorax may occur spontaneously in the absence of these causes.

Your 21 year-old female patient reports that her upper eyelid has been intermittently twitching for the past 2 weeks. She states that these symptoms typically occur before important tests and eventually resolve on their own. What is the MOST likely diagnosis of this ocular condition? Blepharoclonus Hemifacial spasm Blepharospasm Eyelid myokymia

A diagnosis of eyelid myokymia is characterized by the presence of intermittent, unilateral lid twitching or fluttering that may involve either the upper or lower eyelids. This ocular condition can occur as a result of several different triggering factors, most notably fatigue, stress, and increased levels of caffeine. This condition is generally benign and self-limiting, and it typically resolves within a period of several days to several weeks. Blepharoclonus is an ocular condition that is most commonly observed in young children, in which the etiology is frequently unknown. The condition may present as either an increase in blink rate, or increased duration of lid closure upon blinking. Patients diagnosed with blepharospasm will typically present with symptoms of uncontrollable eyelid closures, contractions, or twitches of the eyelid muscles. In some cases, the twitching will radiate to the nose, face, and even the neck area. Twitching in patients with blepharospasm are much more severe than that of eyelid myokymia (which is barely visible). Hemifacial spasm usually occurs in patients in their 5th to 6th decades of life. It is characterized by briefs spasms of the orbicularis oculi muscle, which eventually spreads to involve the facial area in the distribution of the facial nerve.

Which of the following neurotransmitters causes muscle contraction? Dopamine Glutamate Serotonin Acetylcholine

ACH For muscle contraction to occur, Acetylcholine (ACh) is released from the presynaptic terminals of the motor neurons. At the neuromuscular junction, the neuron becomes stimulated, and calcium causes vesicles that contain ACh to fuse with axon endings and release ACh into the synapse. The ACh then binds with receptors on the muscle cell membrane, resulting in muscle contraction. Depleted levels of serotonin have been correlated with depression. Dopamine is a type of catecholamine and plays a large role in Parkinson's disease. This neurotransmitter, if injected intravenously, also stimulates the sympathetic nervous system and causes increased heart rate and blood pressure. Overall dopamine plays a large role in cognition, memory, motivation, and mood to name a few functions. Glutamate is the main excitatory neurotransmitter in the central nervous system and plays an important role in learning and memory.

Accommodation is primarily controlled by which system? The somatic nervous system The parasympathetic system The lymphatic system The sympathetic system

Accommodation is innervated by the parasympathetic system. During accommodation, the parasympathetic system causes contraction of the ciliary muscles which decreases the tension on the zonules causing the lens to become more spherically shaped thereby increasing its dioptric power. Another theory suggests that ciliary body contraction increases the mass in the vitreous which causes the vitreous to push the lens forward. The sympathetic nervous system is primarily responsible for bodily functions in the presence of heightened awareness, danger or excitement and it prepares the body for fight-or-flight. The parasympathetic system is generally in charge of basic housekeeping tasks when the body is at rest. This system essentially tells the body to slow down. The somatic division of the peripheral nervous system is responsible for motor function and serves to convey information to and from skeletal muscles, tendons and skin. This division works closely with the autonomic system which relays signals to visceral organs such as the heart and gut. The lymphatic system plays a large role in the immune system.

Which of the following tests is MOST sensitive for the screening and diagnosis of genital chlamydial infections? Nucleic acid amplification test (NAAT) Enzyme-linked immunosorbent assay (ELISA) Venereal disease research laboratory test (VDRL) Rapid plasma reagin test (RPR) Western blot

According to the Centers for Disease Control and Prevention (CDC), nucleic acid amplification tests (NAATs) are the most sensitive test for the screening and diagnosis of chlamydial infections. NAATs have been shown to be 20-30% more sensitive than previously utilized diagnostic tests (cultures, antigen detection, etc). Venereal disease research laboratory tests (VDRL) and rapid plasma regain (RPR) tests are used in confirming a diagnosis of syphilis. Enzyme-linked immunosorbent assay (ELISA) tests are designed to detect the presence of a certain substance (usually an antigen) and are commonly used in the diagnosis of HIV. Western blot tests detect specific proteins in a given sample and are also frequently used in HIV diagnosis.

Excessive production of the growth hormone during adulthood can lead to which of the following conditions? Pituitary dwarfism Gigantism Marfan's syndrome Acromegaly

Acromegaly Acromegaly is a condition that results from the synthesis and release of too much growth hormone during adulthood. In adults, the plates of long bones have fused and therefore are no longer capable of growth. In response to the growth hormone, bone and connective tissue of the jaw, hands, and feet will grow wider and thicker. The epithelia of the lips, eyelids, nose, and tongue will also continue to grow. Gigantism is caused by excessive release of the growth hormone during childhood resulting in a person that is abnormally taller than the average human. On the other hand, diminished levels of the growth hormone during childhood leads to an adult of small stature but of normal proportion when compared to an average adult (i.e., arms, legs, and body are shorter than an average person but of proper proportion for their body size). People afflicted with Marfan's syndrome have a genetic defect of their connective tissue and tend to be very tall with unusually long fingers and limbs.

Many skin anomalies may mimic malignant lesions. Which of the following skin conditions has the HIGHEST risk of becoming malignant? Papilloma Cutaneous horn Seborrhoeic keratosis Actinic keratosis

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.

Convergence of the eyes occurs with which of the following? Extortion of one eye and intorsion of the other Adduction of one eye and abduction of the other Adduction of both eyes Abduction of both eyes Intortion of both eyes

Adduction of both eyes In vergence movements, the eyes move in opposite directions. In convergence, both eyes adduct (move medially). In divergence, both eyes abduct (move laterally). Intortion of both eyes is known as incyclovergence. If the left eye abducts and the right eye adducts, both eyes are moving to the patient's left; this is called levoversion. If the right eye abducts and the left eye adducts, both eyes are moving right and this is called dextroversion.

Which of the following represents the MOST common type of acquired blepharoptosis? Aponeurotic Mechanical Myogenic Neurogenic

Aponeurotic Aponeurotic (also known as aponeurogenic or involutional) blepharoptosis is the most commonly encountered form of acquired eyelid ptosis (particularly in older adults), representing nearly 60% of cases. It occurs as a result of local dehiscence, stretching, and disinsertion of the levator aponeurosis from its attachments to the tarsus and pretarsal orbicularis muscle. These changes result in a progressive drooping of the upper eyelid. Myogenic blepharoptosis represents only about 4% of cases, while neurogenic etiologies account for roughly 6%, and mechanical blepharoptosis represent around 9%.

What is the MOST common ocular complaint related to the use of oral phosphodiesterase 5 (PDE 5) inhibitors? Conjunctival hyperemia Tunnel vision Dry eyes Bluish tinge to vision Mydriasis Metamorphopsia

Bluish tinge to vision The most common ocular complaint with phosphodiesterase 5 (PDE 5) inhibitors (erectile dysfunction drugs) is a bluish tinge or haze to vision along with increased sensitivity to light. Other ocular side effects can include decreased color vision, blurred vision, central haze, changes in light perception, transient ERG changes, conjunctival hyperemia, ocular pain, mydriasis, retinal vascular occlusions, and subconjunctival hemorrhages. Ischemic optic neuropathy is rare but is the potential side effect causing the most concern.

Which of the following classes of intraocular pressure (IOP) lowering drops should not be used in a patient with an allergy to sulfonamides? Prostaglandins Alpha agonists Miotics Carbonic anhydrase inhibitors Beta blockers

Carbonic anhydrase inhibitors Carbonic anhydrase inhibitors (CAIs) are sulfonamide derivatives; therefore, cautions and contraindications against this class of medication in a patient with a known allergy to sulfa are relevant. There are many other options for treatment in patients who cannot take CAIs; however, if other medications are not effective, or are also contraindication, surgical treatment may then be necessary.

Trichiasis is an inward turning of one or multiple eyelashes towards the eyeball. Which of the following is the MOST common cause of trichiasis? Trauma Entropion Chronic blepharitis

Chronic blepharitis While all of the above options other than lid myokymia can cause trichiasis, the most common cause stems from chronic blepharitis. Trichiasis can cause irritation, discomfort, lacrimation, corneal epithelial defects, and, if left untreated for long periods of time, scarring. Treatment includes epilation, bandage contact lenses, cauterization, electrolysis, cryosurgery, or Argon laser photocoagulation of the offending follicle or follicles. In the event of blepharitis, it is important to prescribe proper lid hygiene.

Trichiasis is an inward turning of one or multiple eyelashes towards the eyeball. Which of the following is the MOST common cause of trichiasis?

Chronic blepharitis Lid myokymia Trauma Entropion While all of the above options other than lid myokymia can cause trichiasis, the most common cause stems from chronic blepharitis. Trichiasis can cause irritation, discomfort, lacrimation, corneal epithelial defects, and, if left untreated for long periods of time, scarring. Treatment includes epilation, bandage contact lenses, cauterization, electrolysis, cryosurgery, or Argon laser photocoagulation of the offending follicle or follicles. In the event of blepharitis, it is important to prescribe proper lid hygiene.

Which of the following antiarrhythmic class of agents is CORRECTLY paired with its mechanism of action? Class III agents (examples include Bretylium®, amiodarone and sotalol); block alpha adrenergic receptors Class I agent (examples include Dilantin®, lidocaine and quinidine); block fast sodium channels Class IV agents (examples include verapamil and diltiazem); decrease duration of action potentials Class II agents (examples include propranolol and metaprolol); block calcium channels

Class I agent (examples include Dilantin®, lidocaine and quinidine); block fast sodium channels Class I agents affect sodium channels which ultimately serve to either lengthen or shorten the duration of the action potential and help to prevent ventricular arrhythmias. Class II agents decrease sympathetic activity on the heart by blocking beta adrenergic receptors and aid in preventing recurrence of myocardial infarction. Class III agents prolong repolarization by blocking potassium channels, thereby preventing arrhythmias. Class IV agents block calcium channels thereby decreasing conduction through the AV node.

Which of the following is an example of a congenital ptosis? Cranial nerve III lesion Cicatricial or scar tissue Involutional Developmental failure of the levator palpebrae superioris Muscle disease such as myasthenia gravis Fat deposits in the upper lid resulting in increased weight of the eyelid

Developmental failure of the levator palpebrae superioris A congenital ptosis generally is the result of a failure of the levator palpebrae superioris (LPS) to develop properly, resulting in an upper droopy eyelid. Acquired etiologies of a ptosis include: Mechanical, such as increased weight of the eyelid making it too heavy for the LPS to lift caused by fat deposition or edema. Cicatricial, caused by injury resulting in scar tissue. Involutional, the LPS begins to degrade as age increases resulting in a loss of function. Myogenic, caused by muscle dystrophies or diseases like myasthenia gravis.

Which of the following BEST describes the physiology behind the first heart sound (also known as the "lub" of "lub-dub)? Opening of the tricuspid and mitral valves Closing of the tricuspid and mitral valves Closing of the aortic and pulmonary valves Opening of the aortic and pulmonary valves

Closing of the tricuspid and mitral valves The primary sounds of the heart are caused by vibrations created by pressure differentials that occur during the closure of the heart valves. The opening of heart valves is typically very slow, occurring without an audible sound, while the rapid closure of the valves creates the "lub-dub" sound that can be easily heard with a stethoscope. The first heart sound ("lub" or S1) arises from the closure of the mitral and tricuspid valves (also known as the atrioventricular valves). The mitral valve closes slightly earlier than the tricuspid valve because contraction of the ventricles begins with the left ventricle. The second heart sound ("dub" or S2) occurs as a result of the closure of the aortic and pulmonary valves (also known as the semilunar valves). The aortic valve closes just before the pulmonary valve due to the fact that the ejection of blood ends first in the left ventricle.

Which 4 of the following drugs are classified as opioid analgesics? (Select 4) Codeine Hydrocodone Acetylsalicylic acid Ibuprofen Morphine Oxycodone

Codeine Hydrocodone Morphine Oxycodone Acetaminophen (Tylenol®) is a non-opioid analgesic that inhibits prostaglandin synthesis. Ibuprofen (Advil®, Motrin®) is a non-steroidal anti-inflammatory drug commonly used for mild pain relief. Acetylsalicylic acid (aspirin) is classified as a salicylate drug that possesses anticoagulant and mild analgesic properties. Morphine, oxycodone, hydrocodone and codeine are opioid analgesics and are derived from the opium poppy or a derivative of it.

Which of the following systemic diseases is MOST commonly associated with the presence of a positive Cogan's lid twitch sign? Multiple sclerosis Myasthenia gravis Grave's disease Systemic lupus erythematosus

Cogan's lid twitch sign is characterized by an overshoot of the upper eyelid on a vertical saccade from down-gaze to the primary position (when the patient first looks downward for a short period of time). The upper eyelid will also often twitch in a nystagmoid fashion or slowly droop back to a ptotic primary position. It is thought that this sign is a result of a transient improvement in lid strength after a short rest of the levator when in downgaze, followed by a drop in the lid in primary position as the levator begins to fatigue again. Cogan's lid twitch is most commonly associated with myasthenia gravis.

Tetracycline should not be prescribed to children because of which of the following potential adverse effects? Depressed bone marrow formation Thromboembolism Urinary tract infections Depressed skeletal growth

Depressed skeletal growth 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; this is yet another reason not to prescribe tetracycline to children. Other common side effects of tetracycline include allergic response, photosensitization, and GI distress. Tetracycline has not been known to cause urinary tract infections (it would actually serve to treat them), bone marrow depression, or thromboembolisms.

Which of the following steroids, when applied topically, is MOST likely to cause in INCREASE in intraocular pressure (IOP)? Dexamethasone Rimexolone Fluorometholone Loteprednol

Dexamethasone Prolonged use of steroids both systemically and topically have been linked to an increase in intraocular pressure (IOP). The mechanism by which this occurs is most likely due to a decrease in the facility of aqueous outflow. Of the steroids mentioned, dexamethasone has the greatest tendency to result in increased IOP. Loteprednol is a steroid that minimally affects IOP and therefore should be used in cases where one is concerned about a potentially damaging rise in IOP.

The following classes of drugs are all considered the first line of treatment for systemic hypertension. Which class is associated with transient myopia? Calcium channel blockers Angiotensin-converting enzyme inhibitors (ACE) Angiotensin receptor blockers (ARB) Diuretics

Diuretics The choice of initial treatment of hypertension is complex and depends on co-morbidities. ACE and ARBs are the current preference. ACE inhibitors are available generically and thus are cheaper, but increasingly ARBs (notably Cozaar® (losartan)) are being made available generically. Calcium channel blockers are popular but less so than ACE and ARB, which work on the Renin system. The finding of transient myopia, while not common, is not altogether rare and should always be considered in patients on thiazide diuretics.

Which of the following is an example of a fortified product? Drinking milk with vitamin D added Eating organically grown food Sitting out in the sun Taking a multi-vitamin daily

Drinking milk with vitamin D added Food and beverage fortification entails the addition of essential micronutrients to foods to increase their nutritional value while posing a minimal risk to health. Many countries (by law) have added vitamins to staple foods to help decrease sickness while promoting health. For example, Canada legally requires that liquid milk and margarine be fortified with vitamin D, because during the winter months where there is minimal sun exposure, many people suffer from hypovitaminosis D. The amount of vitamin D that is added is strictly controlled, as there exists the risk for toxicity if ingested in large quantities.

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? Duane Syndrome Type II OD Duane Syndrome Type II OS Duane Syndrome Type I OS Brown syndrome OS Duane Syndrome Type III OS Bilateral Brown Syndrome

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.

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? Duane type 3 OS Duane type 1 OS Brown syndrome OS Bilateral Brown Syndrome Duane type 2 OD Duane type 2 OS

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.

Which of the following congenital extraocular muscle disorders occurs as a result of failure of innervation of the lateral rectus muscle by the sixth cranial nerve, accompanied by anomalous innervation of the lateral rectus by fibers from the third cranial nerve? Mobius syndrome Duane's retraction syndrome Brown's syndrome Marcus Gunn jaw-winking Congenital fibrosis of extraocular muscles

Duane's retraction syndrome occurs as a result of a developmental error in innervation of the lateral rectus muscle. The sixth cranial nerve fails to innervate the lateral rectus muscle, while at the same time fibers from the third cranial nerve inappropriately innervate the lateral rectus. It is common for this dysinnervation to affect both eyes; however, the involvement of one eye tends to be much more subtle. The clinical signs leading to the diagnosis of this condition include the following extraocular motility defects of the affected eye: - Restricted abduction, which may be partial or complete. - Restricted adduction, which is usually partial. - This occurs secondary to opposing muscles (lateral and medial recti) being innervated by the same nerve, limiting the eye's ability to move. - Retraction of the globe on adduction, which occurs as a result of co-contraction of the medial and lateral rectus muscles, leading to narrowing of the palpebral fissure; on abduction the globe will assume its natural position and the palpebral fissure will open. - Up-shoots or down-shoots on attempted adduction can occur in some cases. This is thought to be caused by a tight lateral rectus muscle that can slip either over or under the globe, producing an anomalous vertical movement of the eye upon co-contraction of the medial and lateral recti. - Convergence deficiency, in which the affected eye remains fixed in primary position while the contralateral eye converges.

A 64-year old male is seen at your office complaining of itchy, red, watery, and burning eyes with crusts around the lashes, especially in the morning. Slit lamp exam reveals trichiasis, lid erythema, collarettes, and interpalpebral injection. You correctly diagnose him with chronic blepharitis. In addition to warm soaks and eyelid scrubs, what medication would BEST help him initially manage his blepharitis? Artificial tears Petrolatum ointment Pred Forte® 1% ophthalmic drops Erythromycin ointment

Erythromycin is a good antibacterial ointment for Gram-positive organisms. It works well for chronic, mild inflammatory cases of blepharitis and has very low potential for toxic and allergic reactions. Other good options would be Polysporin®, Bacitracin, gentamicin, or tobramycin ophthalmic ointments. Petrolatum ointment is good for excessive dryness but would combat neither the bacteria nor the inflammation. Pred Forte® would work well for the inflammatory component but would not help to resolve the infective portion. A good alternative for moderate to severe cases of blepharitis where lid scrubs might be too painful would be topical antibiotic-steroid combinations such as TobraDex®. Artificial tears are always good to keep the eye flushed and clean, but they must be used in conjunction with other regimens.

What is the MOST common type of oculomotor deviation? Esophoria Exophoria Hyperphoria Hypophoria

Exophoria

A 22 year-old male presents with a history of a right orbital medial wall fracture and restriction in right gaze on extraocular muscle testing. Which of the following additional tests is MOST useful in determining whether the limitation is secondary to muscle entrapment or muscle paralysis? Forced duction testing Visual evoked potential Cover test Electrooculogram Exophthalmometry X-ray imaging

Forced duction testing Forced duction testing is an in-office procedure that is used in differentiating between muscle weakness and restrictive causes of limitations in extraocular muscle movements. This test is typically performed when a patient is anesthetized using topical eye drops. The patient is then instructed to look as far as possible in the direction of the muscle that is suspected of underacting such that maximum innervation is recruited to that muscle. The examiner will then use forceps in order to grasp the conjunctiva as close to the area of the limbus as possible, opposite the side of gaze restriction. If the forceps can then rotate the globe further than where the patient can move it on his own, some degree of muscle paresis is likely. However, if the globe cannot be rotated farther, restriction or entrapment of the muscle is probable. For example, if the patient has a deficit in superior gaze, the insertion of the inferior rectus muscle should be topically anesthetized. The patient's gaze should then be directed upwards and the inferior rectus muscle should be grasped with forceps. Further superior rotation of the eye should then be attempted. Resistance is considered a positive forced duction test, while effortless rotation is deemed a negative forced duction test.

When evaluating the function of the levator muscle, it is important to negate the action of which facial muscle? Orbicularis oris Procerus Frontalis Orbicularis oculi Corrugator supercilii

Frontalis The proper technique for evaluation of the levator muscle is to firmly place your thumb against the patient's brow (which acts to negate the action of the frontalis muscle). The patient is then asked to look down as far as possible, placing the ruler to zero at the upper lid margin. While holding the ruler stationary, ask the patient to look up as far as possible and measure where the upper eyelid margin reaches on the ruler. This measurement is also known as the upper eyelid excursion and is typically 15mm or more in normal patients. Good levator function is characterized as 12mm or more, fair is 5-11mm of upper eyelid excursion, and poor levator function is typically 4mm or less.

Which 3 of the following muscles of the face are responsible for retraction of the eyelids? (Select 3) Corrugator Orbicularis oculi Frontalis Muller's Levator palpebrae superioris Your Answer Procerus

Frontalis Muller's Levator palpebrae superioris The eyelid retractors are muscles of the face that serve to open the eyelids. The primary retractor of the upper lid is the levator palpebrae superioris. The levator originates on the orbital roof near the orbital apex. The levator muscle is about 40mm in length with an additional 14-20mm that represents the levator aponeurosis. The aponeurosis splits in the anterior and posterior portions, which insert at the pretarsal orbicularis and the anterior surface of the tarsus, respectively. Muller's muscle is also important in opening the upper lid. It originates underneath the levator aponeurosis and extends to insert at the superior tarsal border. This muscle is responsible for about 2mm of elevation of the upper lid. The frontalis muscle also acts as a weak retractor of the eyelid but is mostly responsible for lifting the eyebrows. By elevating the eyebrows, the frontalis may provide an additional 2mm of retraction of the upper eyelids.

Which of the following eyelid glands are sebaceous glands that secrete sebum into the hair follicle that coats the shaft of the eyelash? Glands of Zeis Glands of Krause Meibomian glands Glands of Wolfring

Gland of Zeis The sebaceous glands of Zeis coat the shaft of the eyelashes and prevent cilia from becoming brittle. The glands of Moll, also known as ciliary glands, are modified apocrine sweat glands found next to the base of the eyelashes and anterior to the meibomian glands. The glands of Moll are prone to blockage and infection which can manifest as a sty. The meibomian glands are sebaceous glands but their function is to secrete the lipid portion of the tear film. The accessory lacrimal glands of Krause and of Wolfring produce an aqueous secretion similar to the main lacrimal gland that contributes to the tear film.

Which of the following BEST describes the actions of the lacrimal system that occur when the eyes close during a blink? Horizontal canaliculi are lengthened, puncta moves temporally, and lacrimal sac collapses Horizontal canaliculi are shortened, puncta moves medially, and lacrimal sac collapses Horizontal canaliculi are lengthened, puncta moves temporally, lacrimal sac expands Horizontal canaliculi are shortened, puncta moves medially, and lacrimal sac expands

Horizontal canaliculi are shortened, puncta moves medially, and lacrimal sac expands As a person closes his eyes during a blink, the pre-tarsal orbicularis oculi compresses the vertical component of the canaliculi and shortens the horizontal canaliculi, which in turn causes the puncta to move medially. Simultaneously, the lacrimal portion of the orbicularis oculi also contracts, which results in expansion of the lacrimal sac. This action creates negative pressure, which draws the tears from the ocular surface through the canaliculi and into the sac.

Herpes zoster is a virus that generally affects only one side of the face. A zoster lesion seen on the tip of the nose is seen as a sign and may signal the presence of ocular involvement roughly 75% of the time. What is the name of this sign? Munson's sign Meyer's sign Horner's sign Hutchinson's sign

Hutchinson's sign occurs when a zoster lesion is seen on the tip or the side of the nose. This sign may signal the presence of ocular involvement. If Hutchinson's is observed, the eye is involved roughly 75% of the time. Conversely, 25% of patients who have a negative Hutchinson's sign will have ocular implications. Munson's sign is seen in keratoconus, although it offers little diagnostic value anymore. Basically, when patients with advanced keratoconus look down, the lower lid will appear 'V' shaped due to central displacement by the protruding cornea. Prior to the characteristic skin eruption seen in measles, the conjunctiva may take on a glassy appearance, followed by swelling of the semilunar fold a few days later. This is known as Meyer's sign.

Which of the following disinfectants is an effective virucidal and is therefore useful in controlling the spread of the Human Immunodeficiency Virus (HIV)? Chlorhexidine Benzalkonium chloride (BAK) Mercurials Hydrogen Peroxide (H2O2)

Hydrogen Peroxide (3%) is a very useful antiseptic and disinfectant. It is also bactericidal and virucidal. Mercurials such as thimerosal are very toxic and only mildly bacteriostatic. Chlorhexidine disrupts the bacterial cell membrane and is useful for the prevention of dental cavities but does not possess virucidal properties. BAK is very commonly used in ophthalmic drop preparations as a preservative. It denatures bacterial cell membranes and therefore, depending on its concentration, can be used as a bacteriostatic agent (low concentrations) or bactericidal or fungicidal agent (high concentrations), but it is not virucidal. It should be noted that the effectiveness of BAK is diminished by soap, blood, and cotton. Because particles of HIV can be found in tears, it is important to disinfect Goldmann tonometer tips. Studies have shown that disinfecting a tonometer tip with 3% H2O2 is effective for HIV and Herpes simplex I and II.

During case history, your 47 year-old Caucasian female patient reports to you that she occasionally manifests double vision in certain fields of gaze. She is taking Tapazole® for Grave's disease and has no other ocular or systemic health issues. Restriction of which of the following extraocular muscles would you MOST likely expect to be causing her symptoms? Lateral rectus Superior rectus Superior oblique Inferior oblique Inferior rectus Medial rectus

IR Thyroid-related orbitopathy associated with Grave's disease (hyperthyroidism) manifests itself through several pathologic features, including the progressive enlargement of the extraocular muscles. This inflammation is mediated through release of cytokines, fibroblast proliferation, increased deposition of extracellular matrix, and differentiation and proliferation of adipocytes, and tends to target the muscles of the eye. Studies have shown that the inferior rectus muscle is preferentially affected in these patients, often resulting in diplopia on upgaze. The second most commonly affected muscle is the medial rectus, followed by the superior rectus then lateral rectus (obliques are rarely targeted). These patients often experience diplopia, proptosis, and orbital pain, and may require surgical intervention.

What class of antibodies are you MOST likely to observe in a patient who is suffering from a bee sting (i.e., a type I hypersensitive reaction)? IgM antibodies IgA antibodies IgG antibodies IgE antibodies IgD antibodies

IgE A type I hypersensitive reaction (a.k.a., anaphylactic, immediate, or IgE-mediated) results when the offending antigen causes production of IgE antibodies, which then attach to mast cells. Subsequent exposure to the antigen causes degranulation of mast cells, resulting in release of histamine, leukotrienes, serotonin, and other allergy and inflammatory mediators. IgM is the antibody responsible for activation of the complement pathway and is the first antibody produced in response to an infection. IgA antibodies are known as the secretory antibodies and are located in mucous membranes. They are primarily responsible for protection of the lungs and gastrointestinal tract from infection. IgA antibodies can also be detected in some mammal's milk transferred for passive immunity. IgD antibodies are typically bound to the surfaces of B-lymphocytes and are only a minor blood component. IgG antibodies are responsible for long-term protection (i.e., from viruses) and are the predominant antibodies found in blood.

Which of the following is the only extraocular muscle that does not originate from the apex of the orbit? Superior oblique Medial rectus Superior rectus Inferior rectus Inferior oblique Lateral rectus

In contrast to the other extraocular muscles (EOMs), the inferior oblique is the only EOM that does not originate from the apex of the orbit. Instead, the inferior oblique muscle arises from the maxillary bone in the medial wall of the orbit. From here, it courses posteriorly and inferiorly to the inferior rectus muscle and inserts into the sclera at a location on the lateral aspect of the globe medial to the tendon of the lateral rectus and posterior to the equator.

A patient with a low AC/A ratio (2/1) displays exophoria 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? -Decrease in exo deviation -The deviation will remain unchanged -Decrease in hyper deviation -Increase in hyper deviation -Increase in exo deviation

Increase in exo deviation The AC/A ratio denotes the amount of change to convergence resulting from a change in accommodation. Regardless of the initial phoria, with decreasing viewing distance the phoria will become more exo (or less eso) for a patient who exhibits a low AC/A ratio. The opposite holds true for a high AC/A ratio (greater than 6/1); as the target gets closer, the resultant phoria becomes more eso or less exo.

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? Inhibition of T-cell activation Antagonism of vitamin K Stabilization of mast cells Inhibition of cyclooxygenase (COX)

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.

Nerve fibers from the abducens nucleus innervate which of the following extraocular muscles? Contralateral superior oblique Ipsilateral superior oblique Ipsilateral lateral rectus Contralateral medial rectus Ipsilateral medial rectus Contralateral lateral rectus

Ipsi LR The nucleus of the abducens nerve (cranial nerve VI) is located in the dorsal lower portion of the pons. Motor neuron axons from the abducens nerve course from this location to the ipsilateral lateral rectus muscle via the cavernous sinus and superior orbital fissure. Additionally, interneurons also traverse from the abducens nucleus to the opposite medial longitudinal fasciculus (MLF) and terminate at the oculomotor nucleus, thus coordinating horizontal gaze movements of both eyes. The trochlear nucleus innervates the contralateral superior oblique muscle. The oculomotor nucleus innervates the ipsilateral medial rectus, inferior rectus, and inferior oblique, as well as the contralateral superior rectus.

Which of the following represents the angle subtended by the visual and anatomical axes of the human eye? Alpha Lambda Omega Kappa

Kappa Angle kappa represents the angle subtended by the visual and anatomical axes of the eye. The visual axis is a line that passes from the center of the fovea, through the nodal point of the eye, and to the point of fixation. The anatomical axis of the eye is a line that passes from the center of the posterior pole through the center of the cornea. Because of the fact that the fovea is typically slightly temporal to the anatomical center of the eye, these 2 axes do not usually line up perfectly. The difference between these is angle kappa. Angle kappa is commonly about 5 degrees and is positive when the fovea is aligned temporally to the center of the posterior pole (resulting in a nasal displacement of the corneal reflex).

Which of the following skin conditions is considered to be benign and has the LOWEST risk of malignancy? Keratoacanthoma Basal cell carcinoma Squamous cell carcinoma Actinic keratosis

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.

When determining a newborn's APGAR score, which 2 of the following are NOT included in the 5 items that the physician evaluates? (Select 2) Reflex irritability Length Color Weight Respiratory effort Muscle tone Heart rate

Length and weight The APGAR scoring system is a quick and accurate way of evaluating a baby's physical status directly after delivery. A physician or nurse will observe 5 signs and record a score for each on a scale of 0-2 based upon the degrees to which the sign is present (0-poor, 1-fair, 2-good). The 5 scores are then added together and range from 0-10. A score of 10 implies that the baby is in the best possible condition. A score of 8 or 9 indicates that the baby is in good condition, 4-7 indicates a fair condition, and 0-3 indicates a poor condition and the need for prompt diagnosis and treatment. The 5 signs are: 1. Heart rate: 0-not detectable, 1-slow (less than 100), 2-Above 100 2. Respiratory effort: 0-absent, 1-slow, irregular, 2-good; crying 3. Muscle tone: 0-flaccid, 1-some flexion of extremities, 2-active motion 4. Reflex irritability: 0-no response, 1-grimace, 2-cry, cough, or sneeze 5. Color: 0-blue, pale, 1-body pink, extremities bluish, 2-completely pink or absence of cyanosis Weight and length of the baby are not related to the APGAR score.

In order to maximize drug penetration through the cornea an ophthalmic drug or its vehicle should possess which property? High pH High alcohol content Highly polar component 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.

Which of the following types of aberration have been shown to play a major role in how the eye detects defocus and responds with the normal reflex accommodative response? Curvature of field Radial astigmatism Longitudinal chromatic aberration Coma Trefoil Spherical aberration

Longitudinal chromatic aberration Studies have shown that longitudinal chromatic aberration (LCA) plays a very important role in how the eyes detect defocus, resulting in an accommodative response. There is a significant amount of LCA present in the human eye; this occurs due to the fact that the refractive index of any medium (other than a vacuum) varies with wavelength. Therefore, shorter wavelengths (blues) will bend more as they pass through a lens, while longer wavelengths (reds) bend less. This leads to a variation in the image location, also known as LCA. If the LCA is removed by using monochromatic light or by optically neutralizing the LCA, it has been proven that a significant disruption occurs in the normal reflex accommodative response.

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? Decreased capillary exchange leads to ionic bonding Reactive oxygen species are increased in the tears of most dry eye sub-types; this increases osmolarity Loss of tear stability induces an increased evaporation rate, leading to increased osmolarity Patients with dry eye tend to blink less than normals, leading to increased evaporation The lipid layer is altered in most dry eye states, leading to ion pairing In aqueous tear deficiency, the lacrimal gland produces more ionic species

Loss of tear stability induces an increased evaporation rate, leading to increased osmolarity 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 2 of the following BEST describe the definition as well as the normal value for the margin-reflex distance 1 (MRD1), which is commonly utilized in the evaluation of a ptosis? (Select 2) The average MRD1 measurement is about 6-6.5mm MRD1 is the distance between the upper eyelid margin and the corneal reflection of a penlight that the patient is viewing directly MRD1 is the distance between the lower eyelid margin and the corneal reflection of a penlight that the patient is directly viewing The average MRD1 measurement is about 4-4.5mm The average MRD1 measurement is about 2-2.5mm

MRD1 is the distance between the upper eyelid margin and the corneal reflection of a penlight that the patient is viewing directly The average MRD1 measurement is about 4-4.5mm The margin reflex distance 1 (MRD1) is the vertical distance between the corneal reflex produced by a penlight that the patient is viewing directly and the upper eyelid margin. MRD2 is the distance from the corneal reflex to the lower eyelid margin. The average MRD1 measurement is about 4-4.5mm, and the average MRD2 measurement is about 5-5.5mm. These measurements are helpful in evaluating potential eyelid ptosis or retraction.

Contraction of the orbicularis oculi to close the eye aids in movement of tears through the lacrimal canaliculi and nasolacrimal drainage system via the action of which section of the muscle? Muscle of Mueller Muscle of Horner Orbital portion of the orbicularis oculi Muscle of Riolan

Muscle of Horner 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 orbital portion of the orbicularis oculi is mainly responsible for forced closure of the eyelids. The muscle of Mueller (also known as the superior tarsal muscle) is a sympathetic smooth muscle that acts to widen the palpebral fissure.

Chronic blepharitis, if left untreated, can cause which of the following structural changes to the anterior ocular segment? Distichiasis Tristichiasis Madarosis Hypertelorism

Madarosis 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.

Your 31-year-old female patient presents with a chief complaint of drooping upper eyelids and irritation that occurs with contact lens wear. Upon slit-lamp evaluation, you evert her eyelids and notice that she has 4+ giant papillary conjunctivitis (GPC). Eyelid ptosis that occurs as a result of severe GPC can be classified as which of the following types of blepharoptosis? Neurogenic Myogenic Aponeurotic Mechanical

Mechanical Blepharoptosis that occurs secondary to either a mass effect weighing down the upper eyelid, or any other condition that provides physical resistance to the action of the levator muscle, is classified as mechanical eyelid ptosis. This type of eyelid ptosis represents approximately 9% of cases seen clinically. The most common etiologies include eyelid trauma, lid tumors, dermatochalasis, and scarring. Floppy eyelid syndrome, and excessive allergic and papillary responses (vernal keratoconjunctivitis, or giant papillary conjunctivitis) also fall within this category.

Which of the following medications occasionally used to treat meibomian gland dysfunction may cause idiopathic intracranial hypertension when taken orally? Cephalexin Minocycline Penicillin Tobramycin Erythromycin

Minocycline Doxycycline, tetracycline, and minocycline belong to the tetracycline class of medications. These antibiotics are frequently used in the treatment of acne, meibomian gland dysfunction, and other infections. Although the mechanism as to why intracranial hypertension occurs remains unclear at this time, all of these medications have the potential to cause idiopathic intracranial hypertension (also known as pseudotumor cerebri or PTC). Because minocycline possesses a high lipid solubility, it has a higher affinity to pass into the cerebrospinal fluid, which may lead to benign (idiopathic) intracranial hypertension. Unlike the typical form of PTC, increased intracranial hypertension as a result of "cycline medication" use occurs equally in males and females and does not have a predilection for overweight females of child-bearing age. The time lag for the development of PTC after the initiation of "cycline" therapy remains unclear, as some patients may displays signs after two weeks of taking the medication while others do not report symptoms until a year has passed after the commencement of therapy. Patients on a "cycline" medication who report headaches, diplopia, or present with sixth cranial nerve palsy or swollen optic nerves should cease taking this medication.

Which 3 tests directly examine the accommodative system? (Select 3) Monocular amps MEM Positive fusional convergence ranges monocular facility testing with +/-2.00D lenses Stereopsis Second-degree fusion

Monocular amps, MEM, monocular facility MEM measures the accuracy of the accommodative response to a given target. Monocular amplitudes and monocular facility also evaluate the performance of the accommodative system. PFC measures the interaction between the accommodative and the vergence system. Stereopsis is a product of binocular retinal disparity. Stereopsis is not a measure of accommodation but serves to evaluate the capability of the eyes to work in unison. Although accommodation must be accounted for when performing this test, stereopsis will not quantify any type of accommodative dysfunction. Stereopsis as a cue to depth works best if the objects are not too far away. In order for stereopsis to occur, the retinal disparity must be within a certain limit to result in a perception of depth. Second-degree fusion 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. The Worth 4 dot is an example of a test that evaluates second-degree fusion. Second-degree fusion evaluates if the eyes are capable of working together and does not measure accommodative capability.

During slit lamp examination, you notice inferocentral bilateral whorl-like yellow/brown corneal epithelial deposits. Your patient is taking several medications. Which of the following medications is MOST likely to be associated with this pattern of corneal deposits? Pacerone® (amiodarone) Zocor® (simvastatin) Glucotrol® (glipizide) Lipitor® (atorvastatin)

Pacerone® (amiodarone) Amiodarone is an anti-arrhythmic medication. Use of this drug commonly causes yellow/brown or white powdery corneal epithelial deposits, located inferocentrally, that appear to swirl outward while sparing the limbus. These deposits minimally affect visual acuity, if at all. The aforementioned deposits can also be observed in Fabry's disease and in patients taking tamoxifen, chlorpromazine, chloroquine and indomethacin.

Sound waves travel through the structures of the ear to the cochlea in which order? Pinna-> oval window-> the incus-> the stapes-> the malleus-> tympanic membrane-> cochlea Pinna-> oval window-> the malleus-> the incus-> the stapes-> tympanic membrane-> cochlea Pinna-> tympanic membrane-> the malleus-> the incus-> the stapes-> oval window-> cochlea Pinna-> tympanic membrane-> the incus-> the stapes-> the malleus-> oval window-> cochlea

Pinna-> tympanic membrane-> the malleus-> the incus-> the stapes-> oval window-> cochlea Sound is funneled by the pinna (the outer ear) into the auditory canal to the tympanic membrane. Vibration of this membrane transfers the sound energy to the malleus (or the hammer) which then passes it to the incus (anvil) and on to the stapes (stirrup). The energy is transmitted to the oval window, which is considerably smaller than the tympanic membrane, causing amplification of the original sound vibrations. The oval window conveys the sound to the cochlea, a fluid-filled, snail-shaped apparatus consisting of the scala vestibuli and the scala tympani, which surround the central cochlear duct. It is within the cochlear duct that the magic happens. The floor of the cochlear duct houses the basilar membrane, which serves as a bed for the organ of Corti. Hair cells of the organ of Corti protrude upwards onto a membrane called the tectorial membrane. Sound waves cause the fluid in the cochlea to move, which vibrates the basilar membrane. This vibration in turn pushes the hair cells against the tectorial membrane, causing the hair cells to bend. The bent hair cells release a neurotransmitter, resulting in action potentials of the auditory nerve. Pressure waves travel through the cochlea and are released to the round window, which helps to release some pressure caused by the force of the sound waves.

You notice a palpable flat elevation of the skin on the left upper lid of your 73 year-old male patient that is about 2.5cm in diameter. What is the proper dermatological term for this type of lesion? Nodule Papule Plaque Vesicle Macule

Plaque - 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).

Oral steroid therapy can retard skeletal maturation and inhibit growth when utilized in children. How can this side effect be MOST EFFECTIVELY minimized without compromising the necessary therapeutic results? Prescribe the therapeutic dose in one sitting every other day Divide the therapeutic dose in half and take twice a day Prescribe the therapeutic dose once a week Substitution of different steroids (i.e. dexamethasone for prednisolone) every two weeks (same dosage)

Prescribe the therapeutic dose in one sitting every other day Alternate day therapy is a good option that allows for minimization or elimination of growth suppression. Alternate day therapy is achieved by prescribing the entire therapeutic dose to the patient every other morning. This prescribing pattern allows for metabolic recovery of the system. However, this type of therapy is ONLY effective for short-acting steroids like prednisone. Triamcinolone and dexamethasone are both long-acting steroids and therefore are not applicable for alternate day therapy. Substitution of different steroids and daily therapy would still result in delayed skeletal maturation because systemic steroid levels would remain high due to continual ingestion.

An infection of the subcutaneous tissue anterior to the orbital septum is known as which of the following ocular conditions? Pyogenic granuloma Preseptal cellulitis Internal hordeolum External hordeolum Orbital cellulitis

Preseptal cellulitis is defined as an infection of the soft subcutaneous tissue anterior to the orbital septum. If an infection occurs anywhere in the orbit posterior to this septum, it is known as orbital cellulitis. An internal hordeolum is a localized infection of the meibomian glands, while an external hordeolum is described as an acute infection with abscess formation of the glands of Zeiss and Moll. A pyogenic granuloma is a proliferative fibrovascular response to prior inflammation, surgery, or trauma.

How does one clinically differentiate between a true Von Graefe's sign and a pseudo Von Graefe's sign? -Ptosis is not present in straight-ahead gaze -Ptosis disappears in down gaze -Ptosis is not evident in adducted gaze -Ptosis is less prominent on abduction

Ptosis is not evident in adducted gaze Pseudo Von Graefe's sign occurs due to aberrant regeneration of cranial nerve III. After incurring an insult (paralysis), upon recovery, instead of innervating the levator palpebrae superioris, fibers now connect to the medial rectus. Therefore, when one adducts the eye on the same side of the palsy, the ptosis is not evident. In straight-ahead gaze a ptosis is present on the same side of the palsy. Von Graefe's sign occurs in Grave's disease (thyroid dysfunction). This term refers to the inability of the eyelid to move down when the globe is directed in a down gaze. It is often described as a lagging of the upper eyelid-not because it sags but because it lags behind movement-wise. The greater the down gaze, the greater the bearing of the sclera. Von Graefe's results from excessive innervation of the sympathetic system causing upper lid retraction via Muller's muscle.

In addition to accommodation, which 2 of the following physiological responses comprise the near reflex (accommodative triad)? (Select 2) Increase in intraocular pressure Pupil dilation Divergence Pupil miosis Convergence Decrease in intraocular pressure

Pupil miosis Convergence In an effort to focus at near, a young eye will undergo three physiologic responses: accommodation, constriction of the pupils (miosis), and convergence of the eyes. These three changes are known as the near reflex, or accommodative triad. Studies have also shown that intraocular pressure (IOP) can increase in response to accommodation (which is why we ask patients to look in the distance when measuring IOP), but this is not part of the classic triad.

A 43-year old woman is seen at your office concerned about the fact that she constantly seems to have styes on her eyelids and her eyes are continually red and irritated. Biomicroscopy reveals meibomitis and blepharitis along with lid telangiectasia and a TBUT of 4 seconds for each eye. She also reports that her cheeks, nose, forehead and chin are easily flushed, especially when exposed to heat or cool temperatures. Given the above findings, what is your tentative diagnosis? Dry eye syndrome Hordeolum Rosacea Systemic lupus erythematosus

Rosacea is a condition that causes excessive blushing of the face, with or without ocular involvement. Rhinophyma (a large, bulbous, red nose) is common in rosacea. Patients will often complain of facial flushing that is exacerbated with extreme temperature exposure, exertion, or the ingestion of hot beverages. This condition is seen two times more frequently in women. Ocular implications commonly include blepharitis, meibomitis, telangiectasia, dry eye syndrome, and occasional corneal involvement such as superficial punctate keratitis, pannus, and neovascularization. Treatment of facial rosacea includes oral tetracycline, topical metronidazole and retinoid compounds. Ocular rosacea is best treated by managing concomitant lid diseases along with artificial tears. While a hordeola and dry eye syndrome do occur in rosacea, these should not be your primary diagnoses. Remember to look at the overall broad picture and not just the pair of eyeballs. Systemic lupus erythematosus (SLE) is an autoimmune disorder that has the capability of affecting many areas of the body. A common finding of SLE is called the malar (or butterfly) rash that is seen in roughly half of the individuals affected by this disorder. This rash generally occurs on the cheeks and over the nose bridge and worsens with ultraviolet light exposure. Concurrent eye conditions with SLE are primarily secondary to complications from the medications used to manage the condition such as oral corticosteroids and anti-malarials.

Which 3 of the following extra-ocular muscles are supplied by the LATERAL muscular branch of the ophthalmic artery? (Select 3) Medial rectus Superior oblique Inferior oblique Inferior rectus Lateral rectus Superior rectus

SO, LR, SR

Weakness of which of the following extraocular muscles is MOST commonly associated with a simple congenital eyelid ptosis? Inferior oblique Superior rectus Lateral rectus Medial rectus Superior oblique

SR Weakness of the superior rectus muscle is the most common ocular motility abnormality associated with a simple congenital ptosis. This is due to the close embryological association of the levator and the superior rectus; these two muscles develop from the same myotome. Keep in mind that extraocular muscle surgery must be performed prior to ptosis correction due to the associated lid position changes that will occur once the eye position is adjusted.

Weakness of which of the following extraocular muscles is MOST commonly associated with a simple congenital eyelid ptosis? Inferior rectus Superior oblique Medial rectus Inferior oblique Superior rectus Lateral rectus

SR Weakness of the superior rectus muscle is the most common ocular motility abnormality associated with a simple congenital ptosis. This is due to the close embryological association of the levator and the superior rectus; these two muscles develop from the same myotome. Keep in mind that extraocular muscle surgery must be performed prior to ptosis correction due to the associated lid position changes that will occur once the eye position is adjusted.

Which of the following most accurately describes the meibomian glands? Sebaceous glands Lacrimal glands Apocrine glands Mucous glands

Sebaceous glands The meibomian glands are sebaceous glands embedded in the tarsal plate of the eyelids that provide the outer lipid portion of the tear film. The pores of these glands open along the lid margin posterior to the cilia. There are approximately 30-40 glands on the upper lid and 20-30 on the lower lid.

A 34 year-old patient presents to your office with a chief complaint of redness and irritation of his eyelids and his eyelashes occasionally sticking together. Upon biomicroscopy, you notice hyperemic and greasy eyelid margins, and soft scales scattered along the eyelid margins and eyelashes. What is the MOST likely diagnosis of this patient's symptoms? Angular blepharitis Staphylococcal blepharitis Bacterial conjunctivitis Meibomian gland dysfunction Seborrheic blepharitis

Seborrheic blepharitis Seborrheic blepharitis - Soft scales are present and located along the eyelid margin and eyelashes - Anterior lid margins appear greasy and hyperemic - Eyelashes commonly stick together Staphylococcal blepharitis - Scales and crusts are typically harder and are mainly located around the base of the eyelashes (collarettes) - Eyelid changes usually occur in conjunction with chronic staph blepharitis, such as scarring and notching, madarosis, trichiasis, and poliosis - Conjunctival hyperemia, papillary conjunctivitis, stye formation, marginal keratitis, phlyctenulosis, tear film instability, and dry eye are also commonly associated with staphylococcus blepharitis Angular blepharitis - Involves the lateral portion of the eyelid - Signs include scaly, red, and macerated skin, with occasional associated papillary and follicular conjunctivitis Meibomian gland dysfunction - Capping of meibomian gland orifices with hyperemia and telangiectasia of the eyelid margin - Tear film is usually oily and froth is commonly observed on the eyelid margin - Pressure on the lid margin will usually result in turbid secretions, and in some cases inspissation is so severe that expression of glands is impossible Bacterial conjunctivitis commonly presents with symptoms of debris on the lashes and eyelashes sticking together; however, signs of mucous and conjunctival hyperemia are usually present.

In a small percentage of patients using timolol for intraocular pressure reduction, the efficacy of the medication may decrease over time. Which of the following terms is used if this decrease in effectiveness occurs within days of starting treatment? Long-term escape Mid-term drift Short-term drift Short-term escape Mid-term escape Long-term drift

Short-term escape In about 10% of cases of patients using timolol (beta-blocker), the efficacy in IOP reduction may decrease over time; this can occur within days of starting treatment (known as short-term escape) or within months of initiating treatment (long-term drift). Recent physiological studies suggest a cellular explanation for these readjustments in tissue responsiveness to the continued use of timolol; however, the precise location of the cells and the interactions of the various adrenergic response elements remain unclear.

Topical anesthetics such as proparacaine are frequently utilized to numb the ocular area, to aid in pain management, or to ensure comfort during certain procedures such as gonioscopy. Prolonged use of proparacaine can cause which of the following adverse effects? Pupil miosis Sloughing of the corneal epithelium Corneal arcus Fuch's dystrophy Cataracts

Sloughing of the corneal epithelium Prolonged use of topical anesthetics applied to the cornea causes softening and loosening of the epithelium. Although this property helps to increase absorption of other drugs such as those used for dilation, overuse can cause severe damage. The junctions between the epithelial cells can become disrupted to the point of corneal sloughing, leading to blurred vision or in severe cases, corneal opacification. Studies have shown that corneal softening occurs to a greater extent with tetracaine than with proparacaine. To date there have not been any correlations between proparacaine use and cataracts, miosis, arcus, or Fuch's dystrophy.

Reflexive blinking is caused primarily by which of the following actions? Inhibition of the orbicularis and stimulation of the levator palpebrae superioris Inhibition of Mueller's muscle and stimulation of the levator palpebrae superioris Stimulation of Mueller's muscle and inhibition of the levator palpebrae superioris Stimulation of the orbicularis and inhibition of the levator palpebrae superioris

Stimulation of the orbicularis and inhibition of the levator palpebrae superioris Reflexive blinking has many etiologies all of which result in stimulation of different pathways, but all of the pathways have one common outcome:closure of the eyelids via 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? -Superior orbital fissure -Internal auditory meatus -Stylomastoid foramen -Superficial temporal artery

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.

The superior palpebral levator muscle is primarily responsible for retraction of the upper lid. Which of the following structures acts as a fulcrum to change the anteroposterior direction of the levator to superoinferior? Inferior oblique muscle Superior oblique muscle Superior transverse ligament (Whitnall's ligament) Superior tarsal muscle (muscle of Muller) Capsulopalpebral fascia

Superior transverse ligament (Whitnall's ligament) The superior palpebral levator muscle is primarily responsible for retraction of the upper lid. The sheath of this muscle blends with the sheath of the superior rectus muscle as it approaches the eyelid at the orbital apex; the superior transverse ligament (Whitnall's ligament) acts as a fulcrum to change the direction of the muscle from anteroposterior to superoinferior in direction. The levator apopneurosis is a fan-shaped fibrous connection that penetrates the orbital septum and extends into the upper lid, anchoring the skin and creating the palpebral sulcus. The capsulopalpebral fascia is the retractor of the lower eyelid and is an extension of the sheath of the inferior rectus muscle and the suspensory ligament. The muscle of Muller (also known as the superior tarsal muscle) is a sympathetic smooth muscle that acts to widen the palpebral fissure.

Which of the following best describes the secondary actions of the inferior rectus muscle? Abduction and intorsion Adduction and intorsion Abduction and extorsion Adduction and extorsion

The inferior rectus muscle originates at the lower portion of the annulus of Zinn and courses to its insertion site, which lies 6.8mm behind the inferior region of the limbus. The primary action of the inferior rectus is depression of the globe; its secondary actions include adduction and extorsion. It is also important to note that when the globe is abducted 23 degrees, the inferior rectus will act solely as a depressor. This is the optimal position of the globe if one wants to isolate the action of the inferior rectus.

The vertical recti muscles are inserted in front of the equator, creating what angle with the visual axis? 51 degrees 19 degrees 23 degrees 67 degrees 39 degrees

The medial and lateral walls of the orbit are positioned at an angle of 45 degrees from each other. The orbital axis then forms an angle of 22.5 degrees with the medial and lateral walls (for the sake of simplicity, this angle is usually regarded as 23 degrees). Therefore, in primary gaze, the visual axis also forms an angle of 23 degrees with the orbital axis. The actions of all of the extraocular muscles depend on the position of the eye as each undergoes contraction. The vertical recti muscles run along the same line as the orbital axis, thereby also creating an angle of 23 degrees with the visual axis at their attachment point anterior to the equator. When the globe is abducted 23 degrees, the vertical recti muscles act purely to elevate or depress the eye

When determining the near point of convergence, which of the following sentences is TRUE? -As the target is moved closer, diplopia is typically reported prior to blurring of the target -The maximal point of divergence is recorded in centimeters as the 'break point' -As the object is moved closer, the accommodative system maintains the target clarity while the convergence system preserves fusion of the object -If diplopia is not reported by the patient, the test should be repeated until the patient reports blurring of the target

The near point of convergence (NPC) is the point in which the patient's eyes are maximally converged. The NPC is determined by presenting the patient with an appropriate accommodative target at near and with the patient's near correction in place, the patient is asked to keep the target clear and single. The target is then brought closer to the patient until either the patient reports that the image of the object appears double or the clinician notes that one of the patient's eyes turns out. This point is measured and recorded from the spectacle plane in centimeters. While performing the NPC, the convergence system maintains fusion of the target and accommodation sustains clarity. Some patients may report blurring of the target (near point of accommodation) prior to experiencing diplopia, but rarely do patients report blurring of the target after experiencing diplopia. The majority of clinicians record 'TTN' or 'to the nose' for patients who do not report diplopia or do not exhibit a break in fusion.

Which cranial nerves are responsible for opening and closing the eye? The trigeminal nerve (CN V) opens the eye and the facial nerve (CN VII) closes the eye The oculomotor nerve (CN III) opens the eye and the trigeminal nerve (CN V) closes the eye The oculomotor nerve (CN III) opens the eye and the facial nerve (CN VII) closes the eye The facial nerve (CN VII) opens the eye and the trigeminal nerve (CN V) closes the eye

The oculomotor nerve (CN III) opens the eye and the facial nerve (CN VII) closes the eye All of the cranial nerves listed have names and numbers correctly matched. The oculomotor nerve innervates the levator palpebrae superioris (which opens the eye), along with Mueller's muscle (which is controlled by the sympathetic nervous system). The facial nerve innervates the muscles of facial expression including the orbicularis oculi, which closes the eye. The trigeminal nerve provides sensory innervation to the eyelids and cornea.

Which cranial nerves are responsible for opening and closing the eye? The trigeminal nerve (CN V) opens the eye and the facial nerve (CN VII) closes the eye The oculomotor nerve (CN III) opens the eye and the facial nerve (CN VII) closes the eye The oculomotor nerve (CN III) opens the eye and the trigeminal nerve (CN V) closes the eye The facial nerve (CN VII) opens the eye and the trigeminal nerve (CN V) closes the eye

The oculomotor nerve (CN III) opens the eye and the facial nerve (CN VII) closes the eye All of the cranial nerves listed have names and numbers correctly matched. The oculomotor nerve innervates the levator palpebrae superioris (which opens the eye), along with Mueller's muscle (which is controlled by the sympathetic nervous system). The facial nerve innervates the muscles of facial expression including the orbicularis oculi, which closes the eye. The trigeminal nerve provides sensory innervation to the eyelids and cornea.

Which 3 of the following bones make up the floor of the orbit? (Select 3) Maxillary Ethmoid Sphenoid Frontal Palatine Zygomatic

The orbital floor consists of three bones: the palatine, maxillary, and zygomatic bones. It is the floor of the orbit that is most susceptible to orbital blow out fractures due to the relative weakness of the posteromedial portion of the maxillary bone. Orbital roof bones: lesser wing of sphenoid, orbital plate of the frontal Lateral wall bones: greater wing of sphenoid, zygomatic Medial wall bones: maxillary, lacrimal, ethmoid, sphenoid

A measure of drug activity that is expressed in terms of the amount of a drug that is required in order to produce a desired response is referred to as which of the following? The efficacy of the drug The potency of the drug The affinity of the drug The reliability of the drug

The potency of a drug refers to the amount of a drug that is required to achieve a desired biological effect. A drug that requires a lower dose is considered more potent than a drug that requires a higher dosage to achieve the same effect. The affinity of a drug for a receptor is a measure of how tightly and how able the drug in question binds to the receptor. Affinity is typically determined by the chemical structure of the drug. The efficacy of a drug is a measure of the drug's ability to produce a biological effect or initiate a biological change once it is bound to the receptor. Efficacy is used to characterize the level of maximal response by a drug.

The power of a thin lens in air can be found by using which of the following equations? The reciprocal of the radius of curvature of the lens in meters The square of the sagittal height of the lens divided by the chord length The radius of curvature subtracted by the primary focal length The reciprocal of the secondary focal length in meters

The reciprocal of the secondary focal length in meters The power of a thin lens in air can be determined using the formula P= n/f' where n=the index of refraction of the surrounding medium, which in the above case is air (1.00) and f'=the secondary focal length.

Which of the following extraocular muscles has its insertion point FURTHEST from the limbus? Lateral rectus Inferior rectus Superior rectus Medial rectus

The spiral of Tillaux is an imaginary line that joins the insertion points of the four recti muscles. As their insertions get further away from the limbus, a spiral pattern is created, starting with the medial rectus. The insertion point for the medial rectus is the closest to the limbus (5.3mm), followed by the inferior rectus (6.8mm), lateral rectus (6.9mm), and finally the superior rectus, which inserts the furthest from the limbus (7.9mm).

While performing the unilateral cover test, the right eye assumes an exo position when covered. If the right eye were to maintain an exo position when the occluder is removed where would the target's image fall on the retina in relation to the fovea? The target's image would be temporal to the fovea The target's image would be nasal to the fovea The target's image would be inferior to the fovea The target's image would be superior to the fovea

The target's image would be temporal to the fovea An exo position places the fovea of the right eye nasal to the image projected from the object of regard. This is due to the outward rotation of the eye which rotates the fovea nasally relative to the object. This places the target's image temporal to the fovea.

Dry eyes can cause blurred vision, stinging and foreign body sensation. How do the tears seen in people with dry eyes compare to those with normal eyes? Increased lysozyme concentration Lower pH than normal Lower osmolarity Higher pH than normal

The tear film in people with dry eyes displays a higher pH than that of normal eyes. The change in pH is attributable to the fact that the osmolarity of the tears increases, thus increasing the pH. Many drug companies have taken advantage of this knowledge and applied it in their manufacture of artificial tears. Alcon, the company that invented Systane, ultilizes a component called Hydroxypropyl-guar (HP-Guar) which is a gel-forming matrix. Upon instillation of Systane into the eye, the liquid transforms into a gel. The difference in pH between the tear film and the artificial tears leads to an alteration in the cross-linking between HP-Guar and borate (another ingredient in the artificial tears), causing the creation of a gel-like layer that allows for increased ocular contact time. Studies show that the tear lysozyme content is decreased in people who suffer from dry eyes.

A patient is seen at your office reporting horizontal diplopia that is worse towards the end of the day. Unilateral cover testing reveals no movement of either eye. Which of the following can correctly be concluded from the above findings? The patient does not likely possess a heterotropia The patient does not likely possess a heterophoria The patient does not likely possess a heterotropia or a heterophoria Further testing is required prior to reaching a conclusion regarding the presence of an ocular deviation

The unilateral cover test (UCT) is useful in diagnosing a heterotropia. If a person does not suffer from a heterotropia, then no movement would be observed on the UCT. A heterophoria would present only on the alternating cover test (ACT).

Which of the following is considered an example of the highest level of fusion? Visual acuity via a Snellen chart Stereoacuity test The Worth-4-Dot test The red lens test

There are 3 degrees of fusion, with third-degree fusion being the highest level. Stereopsis is an example of third-degree fusion. The red lens test and the Worth-4-Dot are both examples of second-degree fusion. Third-degree fusion is the ability to fuse two identical images that are separated by space, creating the perception of depth. The images must be placed at points that cause retinal disparity in order for the perception of depth to occur. Second-degree fusion 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. First-degree fusion is defined as the ability to superimpose two dissimilar objects such that the two objects are perceived to occupy the same space and appear as a combination of the two objects.

What is the MOST common form of an acquired entropion? Involutional Spastic Neurogenic Cicatricial

There are three commonly recognized forms of acquired entropion: involutional, cicatricial, and spastic. Involutional entropion (previously referred to as senile entropion) is by far the most common type of entropion due to degeneration of elastic and fibrous tissue within the eyelid, primarily the tendons at the canthus and the tarsal plate. It almost always affects the lower eyelids, as the tarsal plate is much less rigid than in the upper eyelid. Cicatricial entropion occurs secondary to scarring of the periorbital tissues, which leads to a vertical shortening of the tarsus. Cicatricial changes are most often related to some sort of trauma to the ocular area. Spastic entropion occurs when the orbicularis muscle becomes overactive and hypertrophic. This can occur as a result of blepharospasm, inflammation, irritation, or ocular surgery.

Your patient reports constant epiphora of the right eye. You wish to determine if there is a blockage of her tear drainage system. You perform lacrimal irrigation. During the procedure, the plunger of the cannula is depressed with great difficulty, and the fluid is regurgitated through the puncta that you are irrigating. What is the CORRECT interpretation of these findings? There is a blockage that is proximal to the common caniculus There is an obstruction of the lacrimal duct of the opposite eye The passageway is clear; there is no obstruction at this time There is a blockage that is distal to the common caniculus

There is a blockage that is proximal to the common caniculus Lacrimal irrigation is performed when an obstruction of the tear drainage system is suspected. Dilation of the puncta generally precedes irrigation. Once the puncta is anesthetized and dilated, a cannula is inserted and saline is injected. If the patient reports that they taste saline, or if they cough because of the fluid in their throat, the drainage system is considered open. If the saline is released by the opposite puncta, then there is a blockage located distally to the common caniculus. If the plunger cannot be depressed, or the fluid is expressed by the same puncta that is being irrigated, then the obstruction is proximal to the common caniculus.

Which of the four involuntary vergence stimuli is driven by neural innervation? Proximal Accommodative Fusional Tonic

Tonic vergence is caused by baseline innervation. This type of vergence is generally maintained when all other vergence stimuli are absent. Proximal stimuli are driven by near objects. The response increases as the distance from the object decreases. Accommodative response results from target defocus. Fusional involuntary vergence is provoked by retinal disparity.

Your 73-year-old female patient reports that her primary care physician recently prescribed warfarin for her. She states that they told her that it was important to be consistent with one of the nutrients in her diet, but she can't remember which one. Which nutrient is she referring to? Vitamin K Vitamin C Vitamin A Vitamin B Vitamin D

Vit K Warfarin (Coumadin) is one of the most widely used oral anticoagulants due to its effective systemic absorption, long duration of action, and predictable onset of action. The mechanism of action of warfarin is that it inhibits the activation of clotting factors that depend on vitamin K for synthesis. Certain foods and beverages can make warfarin less effective in preventing blood clots. Specifically, one nutrient that can lessen warfarin's effectiveness is vitamin K. Patients on warfarin should pay special attention to what they eat and they should be consistent in how much vitamin K they ingest daily. The adequate intake level of vitamin K for men is 120 micrograms and 90 micrograms for women. While eating small amounts of foods that are rich in vitamin K shouldn't cause a significant problem, patients should avoid consuming large amounts of certain foods and drinks, including kale, spinach, Brussels sprouts, collards, chard, broccoli, asparagus, and green tea. Alcohol and cranberry juice can increase the effect of warfarin and can subsequently lead to bleeding problems; these drinks should only be consumed in small amounts.

Which of the following vitamins is also known as thiamine? Vitamin B1 Vitamin B6 Vitamin B2 Vitamin B3

Vitamin B1 Vitamin B1 is also known as thiamine. Thiamine is important for carbohydrate metabolism and the maintenance of neuronal tissue. Although rarely seen in the United States due to the fact that most foods are enriched with vitamins, a B1 deficiency can result in beriberi. Symptoms of beriberi include difficulty walking, loss of sensation in hands and feet, paralysis (due to deterioration of myelin sheath), nystagmus, speech difficulty/mental confusion, ophthalmoplegia, and congestive heart failure. Alcoholism can lead to beriberi due to malnutrition. Vitamin B2, also known as riboflavin, aids in the metabolism of nutrients. Avitaminosis B2 can result in decreased visual acuity due to corneal neovascularization, keratoconjunctivitis sicca, or cataract formation. Vitamin B3 (a.k.a. niacin) is responsible for fat and carbohydrate metabolism. A deficiency of Vitamin B3 can cause pellagra, which results in diarrhea, dementia, and dermatitis. Niacin can be used to treat hyperlipoproteinemia. Vitamin B6, also called pyridoxine, serves an important role as a coenzyme for the formation of hemoglobin as well as amino acid and protein metabolism.

Which of the following oral medications has the MOST potential to cause a serious interaction with Amiodarone? Lisinopril Simvastatin Warfarin Zoloft®

Warfarin is an anti-coagulant frequently prescribed to patients with a history of stroke, blood clots, or a heart attack. Amiodarone is an antiarrhythmic drug. When amiodarone is taken concurrently with warfarin, it enhances warfarin's mechanism of action, which can result in dramatically increased clotting times and prolonged bleeding. In the event that the two medications are prescribed simultaneously, it is recommended that the dosage of warfarin be halved. Patients who experience unusual bruising or bleeding, blood in their stool, vomiting, nausea, or dizziness are encouraged to consult with their physician immediately. Other medications that have the potential to interact with warfarin include aspirin, ibuprofen, acetaminophen, heparin, certain antibiotics, birth control pills, and cold and allergy medications. Many supplements may also cause an interaction with warfarin including omega 3 oils, vitamin K, co-enzyme Q10, garlic, wintergreen, St. John's wort, gingko biloba, ginseng, glucosamine, and cranberry extracts.

While several tests such as tear stability and ocular surface staining are global tests diagnostic for the presence of dry eye, what is a specific test that can differentiate aqueous tear deficiency from meibomian gland dysfunction (MGD)? A detailed dry eye questionnaire to allow for score-based symptomology Tear clearance, which is normal in MGD Meibomian gland atrophy/dropout as measured by meiboscopy Conjunctival staining by lissamine green, which is worse in MGD The Schirmer I test, which is considered abnormal if the strip wetting is less than 10 mm in 5 minutes without anesthesia

Whether aqueous tear production is normal or not can be determined using the cotton thread tear test or the Schirmer I test without anesthesia. The Schirmer I without anesthesia essentially becomes a stress test since it is so irritating; if the patient cannot produce aqueous tears under irritating conditions, the main lacrimal gland is probably compromised. Conversely, meibomian gland dropout can be observed in both aqueous tear deficiency and MGD, possibly due to inflammatory processes on the ocular surface.

Which of the following medications should be prescribed to a patient suffering from shingles to help decrease the chances of postherpetic neuralgia? Natacyn® (natamycin) Prednisolone Zovirax® (acyclovir) Viroptic® (trifluridine)

Zovirax® (acyclovir) Postherpetic neuralgia is a painful condition that can last for months to years after the resolution of lesions that occur with shingles. Shingles is caused by the virus Varicella zoster, which causes chicken pox. Shingles are generally experienced by patients who have already had chicken pox and are elderly or immunocompromised. After resolution of chicken pox, the virus lays dormant in the root of the nerves and, for reasons that remain unclear at this time, becomes reactivated later on in life, causing shingles. Shingles presents as lesions on only one side of the body or is limited to a specific dermatome. Initially, one may only first experience a headache followed by tingling, itching, or sensitivity in the affected area. A rash will then develop in this area, followed by lesions that eventually blister over. Lesions do not always appear. Shingles cannot be contracted from one person to another; however, if a person has never been infected with chicken pox, it is possible to contract chicken pox from a person suffering from shingles. Oral antiviral agents like acyclovir, famciclovir or valacyclovir should be initiated within 72 hours of the onset of skin lesions to help minimize the chances of postherpetic neuralgia. Viroptic® is a topical antiviral frequently utilized for Herpes simplex. Natacyn® is an antifungal. Prednisolone, although useful for treating pain associated with shingles, does not help in preventing postherpetic neuralgia.

Which of the following medications can be used to treat lid myokymia (uncontrollable, intermittent lid twitching)? Zyrtec® (cetirizine) Voltaren® (diclofenac) Pred Forte® (prednisolone acetate) Lumigan® (bimatoprost)

Zyrtec® (cetirizine) Oral H-1 antihistamines have several ocular indications. Common H-1 oral antihistamines include Claritin® (loratidine), Zyrtec® (cetirizine), Allegra® (fexofenadine), Clarinex® (desloratadine), and Benadryl® (diphenhydramine). The oral antihistamines serve to alleviate symptoms associated with a Type I allergic response which can include itching, lid edema, chemosis, and excessive tearing. Oral antihistamines can also be recommended for lid myokymia which, although irritating, is not sight-threatening. It is important to distinguish between first generation and second generation oral antihistamines because first generation oral antihistamines (Benadryl®) cause central nervous system (CNS) depression and drowsiness. The second generation oral antihistamines (Claritin®, Zyrtec®, Allegra®, and Clarinex®) are non-sedating as they do not penetrate the CNS. Voltaren® is an NSAID and will not alter the duration of lid myokymia; neither will prednisolone or bimatoprost (Lumigan®).