Vitreoretinal Diseases and Surgery

Diabetic Retinopathy

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), easily identified on an Amsler grid. This condition often necessitates fluorescein angiography in its diagnosis and laser photocoagulation in its treatment

 

Edema (swelling) of the macula
with yellow exudates

 

OCT scan showing edema
(fluid within and under the macula)



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.


 

Abnormal growth of vessels over the optic nerve

 

Ruptured blood vessels with hemorrhage




 
Even worse, these abnormal blood vessels can cause tractional elevation of the retina and produce a retinal detachment. Again, laser photocoagulation is the 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 more extensive retinopathy and increase the risk of visual loss.

Recent scientific evidence gathered through new multicenter clinical trials have now demonstrated that anti-VEGF agents, often used in macular degeneration, now have a leading role in the treatment of macular swelling secondary to diabeties, both in combination with laser and as monotherapy. We also utilize these therapeutic strategies actively in our clinical practices.


For further information, http://www.nei.nih.gov/health/diabetic/retinopathy.asp# 

and http://www.geteyesmart.org/eyesmart/diseases/diabetic-retinopathy.cfm#