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Bascom Palmer Eye Institute

About Diabetic Retinopathy

Anyone with diabetes is at risk for developing diabetic retinopathy. The longer a person has diabetes, the greater their chance of developing diabetic retinopathy. It is the leading cause of blindness in working-aged adults in the United States. Diabetes damages the retina in two ways. The first, known as non-proliferative diabetic retinopathy, occurs when the blood vessels of the retina begin to bleed or leak fluid. This results in retinal swelling (macular edema), small hemorrhages, and the formation of deposits known as exudates.

Diabetic Eyes Brochure
Download the Diabetes and Your Eyes brochure for more information. The second way that diabetes damages the retina is known as proliferative diabetic retinopathy. This is a more severe type of retinal damage. It occurs when blood vessels in the retina or optic nerve become blocked, consequently starving the retina of necessary nutrients. In response, the retina grows new blood vessels (neovascularization). Unfortunately these new vessels are abnormal, causing bleeding or formation of scar tissue. Proliferative diabetic retinopathy may lead to any one of the following:


  • Vitreous hemorrhage – the new vessels bleed profusely into the eye, blocking vision.
  • Retinal detachment – scar tissue pulls on the retina, causing it to tear or detach.
  • Neovascular glaucoma – abnormal blood vessels block drainage of fluid out of the eye, causing high eye pressure.

Symptoms

Early diabetic retinopathy is asymptomatic. A dilated eye exam is the only way to detect changes inside the eye before loss of vision begins. People with diabetes should have an eye examination at least once a year. More frequent exams may be necessary after diabetic retinopathy is diagnosed.
Later stages of diabetic retinopathy may cause the following symptoms:

  • Blurry or distorted vision
  • Floaters
  • Loss of peripheral vision
  • Sudden visual loss

Prevention

The best way to prevent diabetic retinopathy is through strict control of blood sugar and blood pressure. These measures significantly reduce the risk of long-term vision loss. With annual eye exams and prompt treatment of diabetic retinopathy, few people progress to serious vision loss.