Eye: retinopathies Flashcards
what is the leading cause of NEW cases of legal blindness in adults?
diabetic retinopathy (DR) (1/3 of adults >40yo)
major risk factor for developing DR
longer duration of DM, >50% of pt with DM >10-15 yrs
what is the pathogenesis of DR?
basement membrane thickening of retinal arterial capillaries= dec. metabolic exchange & retinal nutrition = weaken vascular walls = microaneurysm & fluid leakage
- closure of capillaries = hypoxia & ischemia
- neovascular tufts
- hemorrhage in preretinal and vitreous space
- traction retinal detachment
what is the earliest clinical sign of DR?
microaneurysms
what are the 8 clinical features of DR?
- microaneurysms (capillary wall outpouch)
- dot/blot hemorrhage
- flame heme
- retinal edema/hard exudate
- cotton wool spots
- venous bleeding
- IRMA- intraretinal microvasc. abnormalities
- macular edema
dot/bot hemorrhage vs flame heme
dot/blot: rupture microaneurysm in deeper layers of retina
flame: rupture in more superficial layer of retina
retinal edema/hard exudates
loss of blood brain barrier
- leakage of proteins, serum & lipids from vessels
cotton wool spots
nerve fiber layer damage
what is the most sig. predictor of progression to PDR?
venous beeding- increasing retinal ischemia
IRMA
intraretinal vascular abnormalities- remodeling of capillary beds w/out proliferation
what is the leading cause of visual impairment for DR?
macular edema
mild vs moderate vs severe nonproliferative DR?
mild- at least 1 microaneurysm
moderate- hemorrhages, microaneurysms, & hard exudates
severe- 4-2-1 hemes: microaneurysms in all 4 quadrants, venous beading in 2 quadrants, IRMA in 1 quadrant
CSME- clinically sig. macular edema - 3 qualifiers
- any edema w/in 500um of fovea
- hard exudates w/in 500um of fovea w/ retinal thickening
- retinal edema > 1disc size and w/in 1disc area of fovea
4 ways to treat/manage DR? which for proliferative DR and ME? which for CSME? which for PDR, vitreal hemes and tractional detachments?
- glucose control
- anti-VEGF (avastin/lucentis) for proliferative and ME
- laser photocoag-for CSME
- vitrectomy - for PDR, persistent vitreal hemes, and tractional detachments
what is the 2nd most likely cause of retinopathy?
HTN- early, advanced and severe forms
early vs advanced vs severe HTN retinopathy
early: vessel wall thickening
advanced: altering caliber of light reflex of arteriorles- “copper wiring”
severe: vessel shunt and A/V compression - “silver wiring”–> hemorrhage, exudate and edema
HTN retinopathy grading 1–>4
- narrowing or sclerosis
- focal narrowing and arteriovenous crossing, exaggerated arterial light reflex
- retinal hemorrhages, exudates, cotton spots. sclerosis and spastic lesions of arterioles
- severe grade 3 & papilledema
management/ txt of HTN retinopathy
control BP
- treat edema & hemes: photocoag, anti-VEGF, corticosteroid injections
what could be a cause of sudden painless unilateral loss of vision (partial or complete)?
vascular occlusion - blockage of retinal vasc
- central artery- loss of vision
- branch artery- partial loss of vision
- central vein vary in manifestation
- branch vein-unilateral blind spot
what would you think if a pt presented with a macular “cherry red” spot and whitening of the retina ?
central retinal artery occlusion (CRAO)
APD
afferent pupil defect: affected eye dilates w/ light instead of contstricts
-shows w/ CRVO and most optic nerve disorders
CRVO- central retinal vein occlusion
blockage = stagnation of blood w/in retina
- hemes in 4 quadrants, tortuous veins (twisted), cottom wool spots, edema, neovasc.
what is the leading cause of irreversible vision loss in adults over 50?
AMD- age-related macular degeneration
- progressive deterioration of central vision due to damage of RPE in macula
- “dry” and “wet”
dry vs wet AMD
90% dry (non exudative): less severe but no txt
10% wet (exudative) : more severe- bleeding & swelling but can txt w/ anti-VEGF injection
dry AMD
90% of AMD cases
RPE disruption from photoreceptor waste product- drusen
geographic atrophy w/ maturation
wet AMD
90% of severe vision loss cases
neovascularization of choroid under macula
hemorrhages & edema
disciform scarring
3 types of drug-induced/ toxic retinopathy
- bull’s eye maculopathy
- crystalline retinopathy
- nutritional amblyopia
bull’s eye maculopathy
drug: plaquenil
- damages macula leading to scotoma (blindspot)
- rare but loss is permanent
crystalline retinopathy
drug: tamoxifen
-crystalline in RPE near macula- hemes and edema
may induce cataract
alcohol/nutritional amblyopia
painless bilateral vision loss
retina may appear normal or have optic nerve pallor
-vision improves w/ supplement
