Diabetic Retinopathy

What Is Diabetic Retinopathy?

Can Cause Vision Loss, Blindness

Diabetic retinopathy is a complication of diabetes and a leading cause of blindness. It occurs when diabetes damages the tiny blood vessels inside the retina in the back of the eye. A healthy retina is necessary for good vision.

If you have diabetic retinopathy, at first you may notice no changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.

Four Stages

The four stages of diabetic retinopathy are

  • mild nonproliferative retinopathy
  • moderate nonproliferative retinopathy
  • severe nonproliferative retinopathy
  • proliferative retinopathy.

(Watch the animation to see how diabetic retinopathy occurs. To enlarge the video, click the brackets in the lower right-hand corner. To reduce the video, press the Escape (Esc) button on your keyboard.)

The first stage is mild nonproliferative retinopathy. At this earliest stage, there are small areas of balloon-like swelling in the retina's tiny blood vessels.

The second stage is moderate nonproliferative retinopathy. As the disease progresses, some blood vessels that nourish the retina are blocked.

The third stage is severe nonproliferative retinopathy. Many more blood vessels are blocked, depriving several areas of the retina of their blood supply. These areas send signals to the body to grow new blood vessels for nourishment.

The fourth stage is proliferative retinopathy. At this advanced stage, the signals sent by the retina for nourishment cause the growth of new blood vessels. These new blood vessels are abnormal and fragile.

The new blood vessels grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye. By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can result.

Other Diabetic Eye Diseases

In addition to diabetic retinopathy, other diabetic eye diseases that people with diabetes may face are cataract and glaucoma.

See this graphic for a quick overview of diabetic eye disease, including how many people it affects, who’s at risk, what to do if you have it, and how to learn more.