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Diabetic retinopathy is the result of acquired damage to the capillary
vessels of the retina. The raised glucose levels in the blood, causes
the accumulation of by-products such as sorbitol that cause damage
to the blood vessels. As a result the vessels block, and leak fluid and
lipids from the vessel walls causing edema to the retina.
Types and Pathogenesis of
Diabetic Retinopathy
The first clinical findings of diabetic retinopathy are microaneurisms
on the vessels of the retina. These take the form of sac-like protru-
sions, where the walls of the capillaries are weakened. There is often
leakage of fluid and often the vessels rupture, causing intraretinal
hemorrhages. The excretion of fluid and lipids from the capillary
walls in conjunction with the body’s defense mechanisms, causes
edema (focal or generalized), as well as yellow candle-wax appear-
ing deposits, called hard exudates.
Background Diabetic Retinopathy (BDR)
© 2015 ATHENS EYE HOSPITAL - NIKOLAOS PAPAZOGLOU M.D.
Microaneurisms
Rupture with bleeding
Normal
With time these hard exudates grow in size and number, and can
pose a threat to sight, if approaching or occupying the macula and
fovea.
The most important cause of reduction in vision due to background
diabetic retinopathy is macular edema.
