Diabetic retinopathy, which has four stages, occurs when diabetes damages the tiny blood vessels inside a certain part of the eye. This complication of diabetes is a leading cause of blindness and is usually diagnosed through a comprehensive visual exam. A major study has shown that better control of blood sugar levels slows the onset and progression of this condition.
Diabetic retinopathy is a complication of diabetes and a leading cause of blindness. Diabetic retinopathy occurs when diabetes damages the tiny blood vessels inside the retina, the light-sensitive tissue at 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.
Diabetic retinopathy has four stages:
- Mild nonproliferative retinopathy. At this earliest stage of diabetic retinopathy, microaneurysms occur. These are small areas of balloon-like swelling in the retina's tiny blood vessels.
- Moderate nonproliferative retinopathy. As the diabetic retinopathy progresses, some blood vessels that nourish the retina are blocked.
- Severe nonproliferative retinopathy. In this stage of diabetic retinopathy, many more blood vessels are blocked, depriving several areas of the retina of blood. These areas of the retina send signals to the body to grow new blood vessels for nourishment.
- Proliferative retinopathy. At this advanced stage of diabetic retinopathy, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They 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.