Eyes Flashcards
What protects the eye?
Bony orbital cavity, eyelids, and lacrimal apparatus
Conjugate movement of eyes refers to
parallel axis of movement in both eyes
Sclera
outer layer of the eye
tough protective white covering
Sclera is continous anteriorly with the
cornea
Cornea
refracting medium- bends light rays to focus on the retina
Cataracts
clouding of the crystalline lens from the clumping of proteins- curable with lens replacement surgery.
What percentage of people have cataracts at age 40 and age 80?
17% of Americans over 40 have cataracts, more than 50% of age 80+. Higher risk in women
Glaucoma
Optic nerve neuropathy characterized by loss of peripheral vision. Caused by increase in IOP.
Age-related macular degeneration (AMD)
Loss of central vision cause by yellow deposits (drusen) and neovascularity in the macula. Risk rises with age and women have a greater risk. Prevents reading, fine work, and distinguishing faces. Peripheral vision is not affected.
Diabetic retinopathy
Results in vision impairment with difficulty driving, reading, and managing diabetes. Prevalence had decreased in the US but will increase worldwide.
What is the leading cause of blindness in working-age adults age 25-74?
Diabetic retinopathy
What are the four most common causes of decreased visual functioning in the aging adult?
- Cataracts
- Glaucoma
- Age-related Macular Degeneration (AMD)
- Diabetic retinopathy
What constitutes visual impairment on the Snellen chart?
Not being able to see 20/50 or below
What groups have higher levels of vision loss and less access to health care than whites?
Blacks and hispanics
In the aging adult. lacrimal glands involute, causing
decreased tear production, a feeling of dryness and burning
presbyopia
Decreased ability of the lens to change shape to accommodate for near vision
What percentage of people have presbyopia by age 40?
50%
Eye function at birth
Limited with macula absent. Eye movements are poorly coordinated
Macula is developed by
developing at 4 months and mature by 8 months
Infant establishes binocularity by
3-4 months
Corneal reflex
stimulation of the cornea causes blinking. Caused by
CN V- afferent
CN VII- efferent to stimulate blinking
Choroid
Darkly pigmented middle layer
Continuous anteriorly with the iris
Highly vascularized to delivery blood to the retina
Iris
controls the amount of light admitted to the retina
Pupil
Normally round and regular.
What CN causes pupil constriction?
CN III
Lens
biconvex disc posterior to the pupil
Serves as a refractory medium, bulges to focus on near objects and flattens for far objects
floaters
common with myopia or after middle age due to condensed vitreous fibers
arcus senilis
gray white arc or circle around the limbus caused by deposition of lipid material
What to ask about for vision changes
onset of floaters, halos around lights, loss of peripheral vision, blind spots
lacrimation
tearing
epiphora
excessive tearing
Adults without eye rx should get a checkup
every 2-3 years
Cigarette smoking associated with what eye diseases?
AMD, cataracts, diabetic retinopathy, eye inflammation
Vision changes: ask about acute onset of:
floaters, halos around lights, loss of peripheral vision, blind spots
What may cause impaired vision?
refractive error
opacity in the media (cornea, lens, vitreous)
disorder in the retina or optic pathway
What can nystagmus indicate?
Disease of the semicircular canals, paretic eye muscle, MS, brain lesions, or an overdose of phenytoin
What does lid lag indicate?
hyperthyroidism
Pallor near the outer canthus of the lower lid may indicate
anemia
scleral icterus
even yellowing of the sclera up to the cornea indicating jaundice
Aniscoria
pupils two different sizes- normal in 5% of people
In older adult, increased of falls and fractures with a distance visual acuity of…
20/25 or greater
pingueculae
Yellowish, elevated nodules caused by a thickening of bulbar conjunctiva from prolonged exposure to sun, wind and dust. Appear at the 9:00 and 3:00 positions, first on nasal side then on temporal side. Common in aging adult
pterygium
opacity on the bulbar conjunctiva that grows over the
ectropion
lower lid dropping away
entropion
lower lid turning in
xanthelasma
soft, raised, yellow plaques on the lids at the inner canthus. Commonly occur around the 50s, more frequently in women. No pathological significance.
Pupils in old age
Small with a slowed pupillary light reflex
Drusen
benign degenerative hyaline deposits common in old age with no effect on vision.
hard exudates
Occur with a more circular or linear pattern than drusen. Abnormal finding
Glaucoma is 15 times more likely to cause blindness among…
Africans Americans between the ages of 45 and 64
Glaucoma screening should begin at age
20 years
open angle glaucoma
drainage canals become clogged over time, causing gradual increase in IOP.
closed angle glaucoma
drainage canals are blocked or covered over by the outer edge of the iris when the pupil enlarges too much or too quickly.
acute closed-angle glaucoma
abrupt onset of symptoms, eye pain, N/V, headache. Individuals can lose their vision in 2-3 hours.
