Opthamology III

Question 1

Diabetic retinopathy

Answer 1

1 cause of blindness in working age adults

Microvascular injury, retinal hemorrhage, capillary leakage, ischemia, neovascularization

2 classes: Non-proliferative and proliferative (more severe; neovascularization; fibrovascular proliferation)

Microaneurysms
Flame hemorrhages
Dot blot hemorrhage common
Diabetic macular edema
Vitreous hemorrhage common (in proliferative)
Hard exudate (lipid leaks from retinal vessels)
Cotton wool spots (capillary ischemia)
Tractional retinal detachment (in proliferative)
Neovascularization of iris (in proliferative)

Question 2

Hypertensive retinopathy

Answer 2

Vasoconstriction (arteriole narrowing)
Arteriosclerosis (copper and silver wiring; arterio-venous nicking)

Acute HTN Retinopathy: retinal hemorrhage, macular edema and exudate, optic disc edema

Vascular occlusions (central retinal vein or central retinal artery)
Flame/splinter hemorrhage
Cotton wool spots (capillary ischemia)

Question 3

Age-related macular degeneration

Answer 3

1 cause of blindness in people >50 years old

2 types: Exudative and non-exudative
Nonexudative: Drusen, RPE changes, atrophy, treat with antioxidants
Exudative (10%): More vision loss; choroidal neovascularization into RPE; treat with anti VEGF injections

Drusen is hallmark (yellow subretinal deposits in macula; lipofuscin/cell waste accumulation)

Question 4

Glaucoma

Answer 4

#1 optic neuropathy 
Associated with elevated IOP 
Nerve fiber layer and optic disc injury
Visual field loss
Cup to disc ratio gets enlarged

Often asymptomatic until end-stage

Management: Screening, lower IOP (meds, laser, surgery)

Question 5

Ischemic optic neuropathy

Answer 5

Acute vision loss in one eye due to infarction of optic disc
Non-arteritic AION – painless
Arteritic AION – Giant cell arteritis

Also: Cotton wool spots (capillary ischemia, small infarcts)
Larger areas of infarcts appear white

Question 6

Symptoms of diseases of the posterior segment

Answer 6

Retinal tear and detachment: starts in peripheral vision that moves towards center

Question 7

Surgical and pharmacologic interventions in the treatment of common diseases of the posterior segment

Answer 7

Surgery to fix retinal tear and detachment

VEGF injections for exudative Age-related Macular Degeneration

Question 8

Retina

Answer 8

Photosensitive neurosensory tissue
Photoreceptors (rods and cones)
Support cells/bipolar cells (connecting cells)
Ganglion cells

Includes: Macula (Fovea and foveola), and peripheral retina (peripheral and night vision, pars plana (posterior ciliary body), and ora serrata (anterior termination of retina))

Question 9

Choroid

Answer 9

Vascular layer that provides metabolic and nutritional support

Includes posterior uvea (iris and cilliary body, choroid) and vascular layer

Question 10

Optic nerve

Answer 10

Cranial nerve 2
Afferent
Synapses with lateral geniculate nucleus and midbrain
Supplied by opthalmic artery

Question 11

Retinal layers

Answer 11

Retinal Pigment Epithelium (RPE): Photoreceptor metabolism, outer blood-retina barrier, potential space

Neurosensory retina: inner layer, light-sensitive cells

Question 12

Retinal vasculature

Answer 12

Central retinal artery (branch of opthalmic, from internal carotid a., inner 2/3 of retina), central retinal vein, capillaries (inner blood-retina barrier)

Question 13

Management of diabetic retinopathy

Answer 13

Glycemic control
BP control
Screening eye Exams
Laser photocoagulation
Anti VEGF injections (improves macular edema)
Pars Plana Vitrectomy (vitreous hemorrhage, tractional retinal detechment)

Question 14

Optic disc

Answer 14

Neural rim
Central cup
Average cup-to-disc ration= 0.3
Symmetrical
98% or normal eyes

Question 15

Papilledema

Answer 15

Bilateral optic disc swelling due to increased IOP
Blurring of disc margin, sometimes surrounding hemorrhage
Can present with or without visual problems
Acutely elevated BP can cause this, brain lesions too