Retinopathies

Question 1

Diabetic retinopathy

Answer 1

• leading cause of new cases of legal blindness in all adults of all age groups
• non-proliferative diabetic retinopathy (NPDR) - mild, moderate, severe
• proliferative diabetic retinopathy (PDR): growing blood vessels where they should not be any
• macular edema and/or clinicall significant macular edema (CSME): can happen at any state and most likely to cause permeate vision loss

Question 2

Risk factors for diabetic retinopathy

Answer 2

• longer duration of DM
• insulin use
• higher A1C
• higher systolic blood pressure
• male
• higher incidence in Hispanic and African American

Question 3

Pathogenesis of diabetic retinopathy

Answer 3

• exact mechanism of action is still unclear
• basement membrane thickening of retinal arterial capillaries gradually interfere w/ metabolic exchange and retinal nutrition
• loss of pericytes of retinal capillaries secondary to excess glucose may weaken vascular walls leading to microaneurysm formation and fluid leakage
• microaneurysms are the earliest clinical sign of DR
• closure of capillaries and precapillary arteroles results in hypoxia and ischemia
• endothelial proliferation bludding gives rise to neovascular tufts
• hemorrhageing into perretinal space and viterous
• fibrous and construction leads to traction retinal detachment

Question 4

Clinical features of diabetic retinopathy

Answer 4

• microaneurysms: capillary wall outpouching
• dot/blot hemorrhages: ruptured microaneuryms in deeper layers of the retina
• flame hemorrhage: rupture in more superficial layer of retina
• retinal edema/hard exudates: loss of blood brain barrier, leakage of proteins, serum, and lipids from vessels
• cotton wool spots: nerve fibers layer infarcts secondary to occulsion of precapillary arterioles - hypoxic
• venous beading: increasing retinal ischemia, most significant predictor of progression to PDR
• IRMA: intraretinal microvascular abnormalities - remodeled capillary beds w/o proliferative changes
• macular edema: leading cause of visual impairment

Question 5

Nonproliferative DR

Answer 5

• mild: presence of at least 1 microaneurysm
• moderate: presence of hemorrhages, microaneuryms, and hard exudates (need all 3)
• severe: hemes, microaneuryms in all 4 quadrants, venous beading in at least 2 quadrants, IRMA in at least 1 quadrants

Question 6

Proliferative DR

Answer 6

• neovascularization
• perretinal hemes: pockets of blood in the space between the retina and posterior face of vitreous
• vitreal heme: diffuse haze
• fibrovascular tissue
• tractional detachment

Question 7

Macular edema

Answer 7

• can be present at ANY stage of DR
• retinal edema within 500um of fovea
• hard exudates withing 500 um of ofvea w/ retinal thickening
• retinal edema greater than 1 disc size and within 1 disc area of fovea

Question 8

DR management

Answer 8

• # 1: glucose control
• anti VEGF tx: for proliferative DR and macular edema: prevents new blood veseel growth
• laser photcoagulation: for macular edema and PRD
• vitrectomy: for PRD, vitreal hemes, and tractional detachment

Question 9

HTN

Answer 9

-increase risk of oocular vascular abnormalities like HTN retinopathy and storkes

Question 10

HTN retinopathy

Answer 10

• arteriolar disease
• increased systemic blood pressure causes anatomical changes to retinal vasculature
• early: HTN leads to vessel wall thickening which leads to attenuation of arterioles
• advanced: manifest by altering caliber and light reflex of arterioles
• severe: blood flow so impaired that nutritional damages occur resulting in hemorrhaging, exudates, and edema

Question 11

HTN retinopathy managment

Answer 11

• control blood pressure

- tx of edema and hemes: laser photocoagulation, anti- VEGF injections or corticosteroid injections

Question 12

Vascular occlusions

Answer 12

• blockage of retinal vasculature, central or branch, either artery or vein
• results in sudden painless loss of vision, partial or complete, temporary or permanent
• Central retinal vein (CRV) vs. central retinal artery (CRA)
• branch retinal vein (BRV) vs. branch retinal artery (BRA)

Question 13

Vascular occlusion risk factors

Answer 13

-HTN
-DM
-hyperlipidemia
-blood clots and certain blood disorders
-blocked carotids
-age over 60
atherosclerosis
-birth control pills

Question 14

Central Retinal Artery Occlusion (CRA)

Answer 14

• unilateral, painless loss of vision
• vision ranges from count fingers to light perception only
• manifests as a whitening of the retina, macular “cherry red” spot, retinal arteriolar narrowing
• may have macular sparing if cilioretinal artery present (32% of population)

Question 15

CRA managment

Answer 15

• lab tests
• poor visual prognosis
• no proven effective tx as eye is dead
• will do workup to find underlying cause

Question 16

Branch retinal artery occlusion

Answer 16

• unilateral, painless, PARTIAL loss of vision
• smaller vessel gets blocked
• edema or whitening along distribution of the arterial branch
• narrowing branch retinal arteriole or appearance of emboi
• management same as CRA
• No TX

Question 17

Central retinal vein occlusion (CRV)

Answer 17

• blockage in the main retinal vein causing stagnation of blood within the retina
• blood has nowhere to go so it explodes out of the vein and goes everywhere
• diffuse retinal hemes in all 4 quadrants, tortuous veins, cotton wool spots, edema, and neovascularization
• Ischemic vs. non-ischemic
• vision can range

Question 18

CRV management

Answer 18

• treat underlying cause (like HTN)
• Tx: PRP for ischemic areas, intraviteral corticosteroid and/or anti-VEGF injections
• The sooner they come in to be tx the better chance they have to get vision back
• left untreated eye will die

Question 19

Branch retinal vein occlusion (BRV)

Answer 19

• unilateral blind spot in the field of vision
• sectoral hemorrhaging along affected venule
• management: tx underlying cause (HTN)
• same work-up and tx as CRV

Question 20

Age related macular degeneration (ARMD)

Answer 20

• leading cause of irreversible vision loss in adults over 50
• progressive deterioration of central vision due to damage to the retinal pigment epithelium in macula
• two forms: non-exudative (dry) and exudative (wet)

Question 21

Age related macular degeneration (ARMD) risk factors

Answer 21

• genetics: abnormal complement factor H
• smoking - 2nd leading cause
• age
• cardiovascular disease / HTN
• obesity

Question 22

Dry/atropic ARMD

Answer 22

• 90% of ARMD cases
• RPE disruption due to waste products from rod and cone cells (Drusen)
• Advanced cases have chorioretinal atrophy
• more likely to get dry than wet

Question 23

Wet/exudative ARMD

Answer 23

• 90% of severe vision loss
• neovascularization of the choroid under the macula
• results in hemorrages and edema
• disciform scarring
• you will see vessels at the macula where there is not meant to be any because it can’t get its supply from choroid anymore

Question 24

Dry and wet ARMD tx

Answer 24

• dry: dietary supplements, antioxidants (no really tx, but can slow it down)
  wet: Anti-VEFG injections, focal laser

Question 25

Drug-induced / toxic retinopathy

Answer 25

• Bull’s eye maculopathy
• crystalline retinopathy
• nutirional amblyopia

Question 26

Plaquenil

Answer 26

• causes Bullseye Maculopathy
• used for malaria, rheumatoid arthritis, and SLE
• it damages RPE cell in the macular leading to scotoma (causes cone damage)
• rare, but vision loss is permanent.
• Higher the dosage the higher the risk
• need an exam every 6 month

Question 27

Tamoxifen

Answer 27

• causes crystalline retinopathy
• used for breast adneocarcinoma
• crystalline in RPE of retina, near macula, results in hemes/edema
• may also induce cataract

Question 28

Alcohol / nutritional amblyopia

Answer 28

• painless bilateral loss of vision
• retina may appear normal or may have optic nerve pallor
• vision usually improves with nutritional supplementation