Diabetic retinopathy is a condition that occurs as a result of damage to the blood vessels of the retina in people who have diabetes. Diabetic retinopathy can develop if you have type 1 or 2 diabetes and a long history of uncontrolled high blood sugar levels. While you may start out with only mild vision problems, you can eventually lose your sight. Untreated diabetic retinopathy is one of the most common causes of blindness in the United States, according to the National Eye Institute. It’s also the most common eye disease in people with diabetes.
What are the types of diabetic retinopathy?
- Nonproliferative diabetic retinopathy (NPDR)
NPDR is also known as background retinopathy. It’s called “nonproliferative” because the eye doesn’t make new blood vessels during the early stages of diabetic retinopathy. During the early stages of retinopathy, damaged blood vessels often leak blood and fluid into the eye. In some cases, the center of the retina, or macula, begins to swell. This causes a condition called macular edema. The three stages of NPDR are mild, moderate, and severe, which may progress to the other type, or fourth stage, proliferative diabetic retinopathy.
- Proliferative diabetic retinopathy (PDR)
Proliferative diabetic retinopathy, or advanced retinopathy, is the stage of retinopathy in which new blood vessels begin to grow within the retina. These new blood vessels are usually abnormal and grow in the center of the eye.
What causes diabetic retinopathy?
High levels of sugar in the blood over long periods cause diabetic retinopathy. This excess sugar damages the blood vessels that supply the retina with blood. High blood pressure is also a risk factor for retinopathy.
The retina is a layer of tissue in the back of the eye. It’s responsible for changing images that the eye sees into nerve signals that the brain can understand. When blood vessels of the retina are damaged, they can become blocked, which cuts off some of the retina’s blood supply. This loss of blood flow can cause other, weaker blood vessels to grow. These new blood vessels can leak and create scar tissue that can cause a loss of vision.
The longer you have diabetes, the higher your chances of developing diabetic retinopathy become. Nearly everyone who has diabetes for more than 30 years will show some signs of retinopathy. Keeping your diabetes under control can help slow the progression.
Women with preexisting diabetes who are pregnant or are planning to become pregnant should have a comprehensive eye exam to determine if they have retinopathy.