Diabetic Retinopathy Flashcards
What is diabetic retinopathy?
A progressive microangiopathy of the retinal blood vessels caused by chronic hyperglycemia
What is the most common cause of moderate to severe vision loss between ages 25 and 74 years?
Diabetic retinopathy
What are the two major layers of the retina?
1) Inner neurosensory retina (NSR)
2) Outer retinal pigment epithelium (RPE)
Where does the retinal blood supply come from?
1) Central retinal artery
2) Choroidal circulation
What is the pathogenesis of diabetic retinopathy?
Microangiopathy which has features of both microvascular leakage and occlusion
Loss of pericytes results in:
1) Distention of capillary wall
2) Disruption of the inner Blood-retinal barrier
Distention of the capillary wall causes __.
Microaneurysms
Disruption of the inner Blood-retinal barrier causes:
Plasma constituents to leak into the retina =
1) Retinal edema
2) Hard exudates
Hypoxic retinas produce:
VEGF (Vascular Endothelial Growth Factor)
What is the hallmark of proliferative diabetic retinopathy
New vessels
With time, the fibrous component of new vessels
contracts and results in:
Traction retinal detachment
Microvascular occlusion leads to:
1) Basement membrane thickening
2) Endothelial cell damage
3) Deformed RBCs
4) Platelet stickiness and aggregation
Early signs of non-proliferative diabetic retinopathy:
1) Microaneurysms
2) Dot and blot hemorrhages
3) Flame-shaped hemorrhages
4) Cotton-wool spots
5) Hard exudates
6) Edema
7) Venous changes (heading and looping)
8) Intraretinal microvascular abnormalities (IRMAs)
What is the EARLIEST clinical sign of diabetic retinopathy?
Microaneurysms
What do microaneurysms look like?
Small red dots in the superficial
retinal layers
A microaneurysm rupture produces:
Dot, blot, and flame shaped hemorrhages