Diabetic retinopathy is the leading cause of blindness for adults in the United States. Even with the best control of one’s blood sugar, a diabetic can still develop retinopathy. Some patients even have retinopathy at the time that they are first diagnosed with diabetes. Background diabetic retinopathy is an early stage of this condition. This type of retinopathy is manifested by damage of the small blood vessels in the retina, usually around the center of the retina (macula). Leakage of blood causes hemorrhages in the retina, and leakage of fluid causes edema (swelling of the retina). Swelling of the retina can reduce vision and cause metamorphopsia(distortion). This condition often fluorescein angiography necessitates in its diagnosis and laser photocoagulation in its treatment.
The more advanced form of diabetic retinopathy is proliferative retinopathy. Progressive ischemia (oxygen deprivation) of the diabetic retina causes the abnormal growth of blood vessels on the retinal surface (neovascularization). Though the blood vessels themselves often cause no change in vision, they can easily rupture and fill the eye with blood (vitreous hemorrhage). This is a major cause of catastrophic visual loss in a diabetic.
Even worse, these abnormal blood vessels can cause tractional elevation of the retina and produce a retinal detachment. Again,laser photocoagulation is treatment of choice for proliferative diabetic retinopathy. For vitreous hemorrhage and retinal detachment, however, vitrectomy is often necessary. The most important factor in preventing the development and progression of diabetic retinopathy is good control of the blood glucose. Hypertension, hyperlipidemia, and pregnancy can result in cases of retinopathy that are more severe, and can increase the risk of visual loss.