Diabetes and the Eye - Margalit

Question 1

What is the macula?

Answer 1

area of the retina responsible for detailed, fine central vision - made of rods and cones

Question 2

What is the fovea?

Answer 2

the center of the macula

high density of CONES, NO rods

Question 3

Describe Microaneurysms

Answer 3

saccular out pouching at the site of capillary degeneration

earliest ophthalmoscopic manifestation of diabetic retinopathy

Question 4

Describe Macular Edema

Answer 4

breakdown of the inner blood-retinal barrier - allowing leakage of fluid and plasma constituents into the surrounding retina

can occur in non-proliferative and proliferative diabetic retinopathy

Question 5

Macular Edema Treatment

Answer 5

LASER

• zaps leaking microaneurisms - no treatment of foveal avascular zone
• marked absorption of fluid and lipids
• lipids take longer to disappear by macrophages

Intraocular Steroid Injections

• stabilizes endothelial cells and blood-retinal barrier
• reduces immune and inflammatory response

VEGF Inhibitiors

• inhibits vascualar endothelial growth factor - reudcing neovascualrizaation

Question 6

Changes in NON-PROLIFERATIVE diabetic retinopathy

Answer 6

• macular edema
• changes result due to retinal ischemia and capillary obliteration
• COTTON WOOL SPOTS
• acute swelling of axons
• intra-retinal microvascular abnormalities - dilation and duplication of the capillary bed
• venous beading (irregular diameter of retinal venules)
• capillary closure and dropout - increases Foveal Avascular Zone

Question 7

Non-Surgical Means of Managing

Non-Proliferative Diabetic Retinopathy

Answer 7

Tight glycemic control

Rx hyperlipidemia

Control hypertension

Question 8

Disease states in which vascular changes are seen:

Answer 8

CVO - central retinal vein occlusion

BVO - branching retinal vein occlusion

Sickle Retinopathy

Coats’ Disease

Hypertension

Sarcoidosis

Radiation Retinopathy

Hyperviscosity Syndromes

Collagen Vascular Disorders

Question 9

Pathogeneis of Prolfierative Retinopathy

Answer 9

Question 10

Nevoascularization Elsewhere

Answer 10

occurs with

• severe venous beading
• intraretinal hemorrhages
• can occur anterior to the retina and into vitreous humor (which can apply traction to the NVE)

Question 11

Nevoascularization of the Disc (NVD)

Answer 11

• pre retinal hemorrhage (anterior to retina and into the vitreous)
• larger fibrous component
• can cause traction of the retina
• can also be present with clinically signficant macular edema

Question 12

Outcomes of Proliferative Retinopathy

Answer 12

traction retinal detachment

vitreous hemorrhage

neovascular glaucoma

Question 13

Pathophysiology of traction retinal detachment and vitreous hemorrhage

Answer 13

1. neovascularization anterior to the retina
2. the posterior cortical vitreous contracts

this may induce hemorrhage - the blood will collect in the subvitreous space or vitreous cavity

Question 14

Treatment of Proliferative Retinopathy

Answer 14

Viterectomy

Pantretinal Photocoagulation

VEGF Inhibitiors

Question 15

Treatment of Proliferative Retinopathy:

Viterectomy

Answer 15

indications:

• tractional retinal detachment threatens the macula
• non-clearing vitreous hemorrhage

Question 16

Treatment of Proliferative Retinopathy:

Panretinal Photocoagulation

Answer 16

may induce the regression of fibrovascular tissue - therefore decrease the likelihood of

• traction detachment
• vitreous hemorrhage
• neurovasuclar glaucoma

Question 17

** Epidemiology **

as the duration of diabetes increases

• the rate of proliferative diabetic retinopathy ________
• the occurance of macular edema ________

Answer 17

increases

increases

Question 18

Glycemic Control in Diabetic Retinopathy

Answer 18

• cannot completely prevent the occurance of retinopathy
• reduction in the rate of progression
• 35-45% reduction in risk of retinopathy progression for every 10% decrease in HbA1C

Question 19

Other Risk factors for Diabetic Retinopathy (4)

Answer 19

Hypertension

Hyperlipidemia

Pregnancy

Anemia