Diabetic retinopathy is a complication of diabetes that can cause vision problems. Excessive sugar in your blood, also known as blood glucose, can damage blood vessels in your eyes. More specifically, high blood sugar damages the blood vessels of your retina, which is the light-sensitive tissue lining the inside of your eye at the back of your eye. High glucose can even damage your macula, which is the region of the retina responsible for sharp, central vision.
Damaged blood vessels can swell and leak, or they can close completely to prevent blood from passing through. Sometimes abnormal blood vessels can develop to cause diabetic retinopathy.
Diabetic retinopathy has two main stages. Non-proliferative diabetic retinopathy (NPDR) is the first phase of the disease – many individuals with diabetes have NPDR. When you have NPDR, the tiny blood vessels in your retina leaks, and this makes your retina swell. Proliferative diabetic retinopathy (PDR) is the more advanced stage of diabetic eye disease, and it occurs when new blood vessels appear in the retina.
Symptoms may not appear in the early stages of diabetic retinopathy, or mild symptoms may develop. The disease can cause blindness eventually.