Chapter 16 - Assessing Eyes
POAG Risk Factors
-Increased Intraocular pressure above 21 mmHg -African American, Mexican American, Asian American ethicnity -Advancing age -Family history of glaucoma -Diabetes -Hypothyroidism -Eye injuries, tumors, inflammatory processes -Prolonged corticosteriod use -nearsightedness
Risk Factors of Cataracts
-Increasing age -Exposure to ultraviolet B light -Diabetes mellitus -Cigarette smoking -Alcohol use -Diet low in antioxidant vitamins -High blood pressure -Eye injuries/surgery -Steroid use -Female gender -Persistent diarrhea -Gout -Abdominal obesity -Beta blocker use
Causes of Glaucoma
-eye injury -inflammation -tumor -advanced cataracts -diabetes may also be an unknown cause
Cataracts
-leading cause of blindness -clouding of the usually clear lens of the eye, causing a person to see as though looking through a frosty or foggy window.
myopia
-nearsightedness, impaired far vision -second number on acuity result is larger than the first ex 20/40
Normal Eye Pressure
10 - 21 millimeters of mercury
Ophthalmoscope
An instrument used to look inside the eye
anisocoria
An unequal size of the pupils (less than 0.5 mm difference) is normal, greater in dim light compared to bright light, Causes: trauma, tonic pupil and oculomotor nerve paralysis.
Corneal light reflex
Assesses parallel alignment of the eyes. Reflection of light on corneas should be in the exact same spot. Irregularities: may be due to muscle weakness or paralysis.
Sudden Vision changes
Changes associated with head trauma or increased intracranial pressure
Gradual Vision changes
Changes that may be related to aging, diabetes, hypertension, or neurologic disorders
E Chart
Chart used by children and non English speaking patients. Scored same as snellan
Spots or floaters
Common among clients with myopia or in clients over 40
sclera
Dark-skinned clients may have _______ with yellow or pigmented freckles.
presbyopia
Farsightedness, impaired near vision, occurs when client must move the client further than 14" -caused by decreased accommodation -common in clients over 45 years of age
retina
Inner lining of the eye that receives the images formed by the lens and transmits those images to the brain through the optic nerve. Contains rods and cones, specialized nerve cells that are responsive to light
oculus sinister
Left Eye: pupillary reaction in fraction form Ex. 3/2 Top number indicates size of pupil at rest Bottom number indicates the constricted size
pupillary light reflex
Normal constriction of the pupils when bright light shines on the retina
Lutein and zeaxanthin
Nutrients that reduce the risk of chronic eye diseases including macular degeneration and cataracts Foods: Kale, spinach, collards, turnip greens, corn, green peas, broccoli, romaine lettuce, green beans, eggs, and oranges
oculus dexter
Right Eye: pupillary reaction in fraction form Ex. 3/2 Top number indicates size of pupil at rest Bottom number indicates the constricted size
consensual pupil response test
Test pupillary reaction to light: while client looks straight ahead, approach each eye from the client's side with a penlight. Observe the pupillary reaction in the opposite eye.
direct pupil response test
Test pupillary reaction to light: while client looks straight ahead, approach each eye from the client's side with a penlight. Observe the pupillary reaction.
optic chiasma
The cross-shape where some of the information from the left and right eye crosses over to pass into the opposite side of the brain.
21mm, 2 mm
The eyes of African Americans protrude slightly more than those of Caucasians, and African Americans of both sexes may have eyes protruding beyond ____. A difference of more than _____ between two eyes is abnormal.
Acute angle-closure glaucoma (AACG)
Type of Glaucoma: Signs and Symptoms: -severe eye or eyebrow pain -severe headache -nausea and vomigting -sudden onset of visual disturbance, often in low light -blurred vision -rainbow halos around the lights -reddening of the eye
Cover Test
Use opaque card to cover an eye to observe for eye movement. Eyes should remain fixed and should not have to move to reestablish focus
pinguecula
Yellowish nodules on the bulbar conjunctiva. These harmless nodules are common in older clients and appear first on the medial side of the iris and then on the lateral side.
Optic nerve discs
____________are larger in Blacks, Asians, and Native Americans than in Hispanics and non-Hispanic whites.
Cyanosis
__________of the lower lid suggests heart or lung disorder
Scotoma
a blind spot that is surrounded by either normal or diminished peripheral vision.
iris
a circular disc of muscle containing pigments that determine eye color
Glaucoma
a group of eye conditions resulting in optic nerve damage usually caused by abnormally high intraocular pressure. -Second leading cause of blindness.
episcleritis
a local, noninfectious inflammation of the sclera. The condition is usually characterized by either a nodular appearance or by redness with dilated vessels.
arcus senilis
a normal condition in older clients, appears as a white arc around the limbus. The condition has no effect on vision.
eye orbit
a round, bony hollow formed by several different bones of the skull
caruncle
a small, fleshy mass that contains sebaceous glands
Optic atrophy
a white-colored disc without vessels and is seen with the death of the optic nerves.
Jaeger Test
acuity test for near vision, holds newspaper 14 inches away
Ectropion
an everted lower results in exposure and drying of the conjunctiva. Interferes with normal tear drainage.
Entropion
an inverted lower lid, may cause pain and injure the cornea as eyelashes brushes against the conjunctiva and cornea. Interferes with normal tear drainage.
Nystagmus
an oscillating (shaking) movement of the eye - may be associated with an inner ear disorder, multiple sclerosis, brain lesions or narcotics use.
Positions Test
assesses eye muscle strength and cranial nerve function / extraocular movements. Eye movement should be smooth and symmetric
lens
biconvex, transparent, avascular, encapsulated structure located immediately posterior to the iris
Intermittent blind spots
blind spot associated with vascular spasms or pressure on the optic nerve by a tumor or intracranial pressure
Consistent blind spots
blind spots that may indicate retinal detachment
trigeminal nerve
carries the afferent sensation into the brain, supports the corneal reflex
facial nerve
carries the efferent message that stimulates the blink
Glaucoma
causes enlarged physiologic cup
pupil
central aperture of the iris
Snellen Chart
chart used for testing distance vision; contains letters of varying size and is administered from a distance of 20 feet; a person who can read at 20 feet, what the average person can read at this distance is said to have 20/20 vision
lacrimal apparatus
consists of glands and ducts that lubricate the eye
ciliary body
consists of muscle tissue that controls the thickness of the lens, which must be adapted to focus on objects near and far away
Strabismus
constant malalignment of the eyes
direct reflex
constriction occurs in the eye exposed to light
bulbar conjunctiva
covers most of the anterior eye
optic disc
cream-colored, circular are located on the retina, where the optic nerve enters the eyeball.
Vitamin C
decrease the risk of cataracts and reduce the risk of age-related macular degeneration
sclera
dense, protective, white covering that physically supports the internal structures of the eye.
diplopia
double vision, may indicated increased intracranial pressure due to injury or a tumor
ptosis
drooping of the upper lid Seen with: oculomotor nerve damage, myasgthenia gravis, weakened muscle or tissue or a congenital disorder.
Epiphora
excessive tearing caused by exposure to irratants or obstruction of the lacrimal apparatus.
indirect or consensual light
exposure to the light in one eye results in constriction of the pupil in the opposite eye
accommodation
functional reflex allowing the eyes to focus on near objects
Conjunctivitis
generalized redness of the conjunctiva "pink eye"
chalazion
inflammation of meibomian glands may produce extreme swelling of the lid
medial canthus
inner point that joins eyelids; contains puncta and caruncle
esotropia
inward turn of the eye
palpebral conjunctiva
lines the inside of the eyelids
lacrimal gland
located in the upper outer corner of the orbital cavity, produced tears
Macular degeneration
major cause of visual impairment that affects the macula portion of the retina
Primary Open-Angle Glaucoma (POAG)
most prevalent type of glaucoma Signs and symptoms: -gradual loss of peripheral vision, usually in both eyes -tunnel vision in the advanced stages
Oblique Muscles
muscles responsible for diagonal movement
Rectus Muscles
muscles responsible for straight movement.
visual perception
occurs as light rays strike the retina, where they are transformed into nerve impulses, conducted to the brain through the optic nerve, and interpreted
exotropia
outward turn of the eye
Eyelashes
projections of stiff hair curving outward along the margins of the eyelids that filter dust and dirt from air entering the eye.
Vitamin E
protect cells of the eyes from damage caused by unstable molecules. Foods: Nuts, fortified cereals, and sweet potatoes
exophthalmos
protrusion of the eyeballs accompanied by retracted eyelid margins -characteristic of Graves' disease
visual field
refers to what a person sees with one eye
meibomian glands
secrete an oily substance that lubricates the eyelid
Halos
seen around lights, associated with narrow-angle glaucoma
extraocular muscles
six muscles attached to the outer surface of each eyeball that control six different directions of eye movement.
Rods
specialized nerve cells, regulated black and white vision
Cones
specialized nerve cells, regulated color vision
hordeolum
stye or inflammation of glands in lid
Papilledema
swelling of the optic disc, appears as a swollen disc with blurred margins, seen with hypertension or increased intracranial pressure -visible and numerous disc vessels -lack of visible physiologic cup
lacrimal canals
tears empty into the __________________
limbus
the point where the sclera meets the cornea
conjunctiva
thin, transparent, continuous, membrane that is divided into two portions: a palpebral and a bulbar portion.
corneal reflex
touch cornea with cotton wisp produces blinking or tearing
cornea
transparent layer, permits the entrance of light, which passes through the to retina.
Night blindness
trouble seeing at night, associated with optic atrophy, glaucoma and Vitamin A deficiency
eyelids
two movable structures composed of skin and two types of muscle: striated and smooth. Purpose is to protect eye from foreign bodies and limit the amount of light entering the eye.
puncta
two small openings that allow drainage of tears into the lacrimal system
Phoria
used to describe misalignment that occurs only when fusion reflex is blocked.
Amsler Test
used to evaluate visual field defects
Tonometry
used to measure pressure within the eye
blepharitis
waxy, white scales (seborrheic) or inflammation of hair follicles (Staphylococcus aureus) causes local redness, swelling or pain
palpebral fissure
white space between open eyelids
Acuity Result
written like: 20/20 First number indicates the distance from the chart Second number refers to the last line that could be read.