eye Flashcards
epithelial layer surrounding sclera that produces mucous to lubricate eye
conjuctiva
lens attached to
ciliary body/ciliary muscles:
allows for accomodation (focus far/near objects)
uvea contents (behind sclera)
iris
cilliary apparatus
choroid (vascular layer posterior to retina)
fluid posterior to lens
vitreous humor (body)
fluid in anterior chamber + posterior chamber
aqueous humor
anterior to iris
anterior chamber
posterior to iris, anterior to lens
posterior chamber
abrupt onset of eye pain, headache (eyebrow→temporal), nausea, colored halos, rainbows around light
red, teary eye with hazy cornea and fixed, mid-dilated pupil (not reactive to light)
eye firm to palpation
acute angle-closure glaucoma (closed-angle, narrow-angle)
EMERGENCY!
insdidious (yrs) - usually bilateral
early: asymptomatic, elevated intraocular pressure
late: ↑ IOP → damages optic nerve → gradual loss of PERIPHERAL vision, permanent blindness if untreated
open-angle glaucoma (wide-angle)
more common
treatment of acute angle-closure glaucoma: inhibit aqueous humor production, improve outflow of aqueous humor
laser iridotomy (holes in iris, allow fluid to flow from posterior to anterior chamber→ TM)
if >1 hr before iridotomy:
↓ aqueous humor production: eye drop timolol (DOC - B blocker) or oral acetazolamide (carbonic anhydrase inhibitor diuretic)
↑ outflow of aqueous humor:
PG-F2α (DOC) or apraclonidine (α agonist) or pilocarpine (cholinergic agonist)
↓ IOP rapidly: mannitol
laser trabeculoplasty: holes into TM to improve outflow
risk factors for open-angle glaucoma
>40 yo african american family hx of glaucoma myopia diabetes
screening for glaucoma
fundic exam: optic cup:disc ratio
enlarged optic cup: >50% diameter of optic disc
fundoscopic exam
yellow circle = optic disc = optic nerve
bright white circle inside optic disc = optic cup
Normal: optic cup
loss of CENTRAL vision
peripheral vision intact
age-related macular degeneration
drusen accumulates between retina and choroid → gradual loss of vision
dry age-related macular degeneration
rapid onset and progression
neovascularization of choroid → vessels bleed and damage photoreceptors
wet age-related macular degeneration
risk factors for macular degeneration
smoking
treatment of macular degeneration
stop smoking
antioxidant: B carotene, vitamin C, lutein, selenium, zinc
Wet: injection of anti-vascular endothelial growth factor (anti-VEGF) into vitreous humor OR laser therapy
cotton wool spots
focal areas of retinal ischemia possibly caused by:
diabetes
HTN
well-defined, bright yellow exudates
flame hemorrhages
cotton wool spots
diabetic retinopathy
neovascularization (proliferation of new blood vessels) → can rupture, bleed, scar
proliferative diabetic retinopathy
causes of retinal detachment
trauma
diabetes
sudden onset of flashing lights, floaters → ↓ vision
wrinkled retina
retinal detachment
must surgically reattach
loss of red reflex (white reflex instead) in one eye of child or infant
retinoblastoma
swelling of optic disc
blurry margins
physical exam finding that suggests ↑ICP from brain tumor or pseudotumor cerebri
papilledema
painless vision loss → pale retina (ischemic retina) with “cherry red spot” on macula (retina is thin at macula, able to see choroid behind retina)
central retinal artery (+ vein run through optic nerve) occlusion:
ischemia of eye
cherry red spot on retina
central artery occlusion
Tay Sachs disease
Niemann Pick
other lysosomal storage disorders: accumulation in ganglia of macula (gives red color)
opacification of lens - usually bilateral
slowly progressive, painless ↓ in vision
first sign: near-sightedness (don’t need reading glasses any more)
difficulty driving at night, reading road signs, reading fine print
sun or oncoming headlights at night cause disabling glare
cataracts
risk factors for cataracts
age long-term GC use tobacco alcohol diabetes
diabetic complications of eye
retinopathy
glaucoma
retinal detachment
cataracts
refractive structures that help to focus light on retina
cornea
lens
accumulation of lipid
white/blue ring in periphery of cornea
arcus senillis (in elderly)
clouding of cornea
mucopolysaccharidoses (lysosomal storage disease - accumulation in cell of cornea)
iris pain and redness
photophobia
pus in anterior chamber (cornea)
anterior uveitis (iritis)
seronegative spondyloarthropathies: reactive arthritis or ankylosing spondylitis (HLA-B27)
sarcoidosis
juvenile idiopathic artheritis
anterior uveitis (iritis)
associated with CMV, toxoplasma, cat scratch disease (bartonella), psoriatic arthritis, IBD arthritis (HLA-B27)
posterior uveitis (chorioretinitis if retina involved too) behind retina
allergies/infection → inflammation → capillaries of conjuctiva dilate → pink eye
conjunctivitis
adenovirus (viral infection usually)
bacterial (unilateral, pus around eye)
allergic (+ allergic rhinitis in spring/fall)
conjunctivitis