An Overview of Diabetic Retinopathy

Diabetic retinopathy, a leading cause of blindness in adults in the U.S., is a disease of the retina brought about by diabetes. It is caused by prolonged high blood sugar levels and usually gets progressively worse through the years.

What causes diabetic retinopathy and what happens to your eyes?

High levels of blood glucose can cause blood vessels in your retina to swell, weaken, burst and leak blood into your eye. Or abnormal new blood vessels may grow on the retina and leak. The leaking blood causes your vision to become blurry, or you may see spots of blood called "floaters." In time you may even lose your vision altogether. High blood pressure can also damage weakened blood vessels in eyes and worsen the effects of diabetic retinopathy.

Diabetic retinopathy can also lead to retinal detachment and macular edema. When bleeding from the blood vessels causes scar tissue to form, the tissue can pull on the retina and detach it from the wall of the eye. The macula is the middle part of the retina and can swell as a result of retinopathy, leading to blurred vision and blindness.

Stages of diabetic retinopathy

There are four stages of diabetic retinopathy. During mild non-proliferative retinopathy, the earliest stage of the disease, small areas of the blood vessels begin to swell.

As the disease progresses to moderate non-proliferative retinopathy, retinal blood vessels become blocked.

During severe non-proliferative retinopathy, more blood vessels are blocked, which signals the body to grow new blood vessels on the retina.

When the disease progresses to an advanced stage, or proliferative retinopathy, weak new blood vessels grow on the retina. If these fragile blood vessels break and leak blood, it can cause severe vision loss or blindness.

Symptoms, prevention and treatment

It's hard to imagine, but there are usually no symptoms of diabetic retinopathy and no pain. You can even be in the proliferative stage of the disease and not yet have any symptoms. That's why it's critically important to have a dilated eye exam at least once a year if you have Type 1 or Type 2 Diabetes.

If you are in one of the first three stages of the disease, you will likely not require treatment, just frequent eye exams. However, you can prevent the progression of diabetic retinopathy by lowering your blood sugar, blood pressure and bad cholesterol (LDL) levels.

If you do have proliferative retinopathy, the earlier you receive treatment, the better your chances of saving your vision. In fact, you can decrease your risk of blindness by 95 percent if you see your doctor before you experience any vision loss.

If you have non-symptomatic proliferative retinopathy, or if the bleeding is not yet severe, you will likely be treated with laser surgery to shrink the abnormal blood vessels. If you have a lot of bleeding in your eye, you may instead have a vitrectomy, a surgical procedure in which blood is removed from the center of your eye.

While both treatments have high success rates for reducing vision loss, it is important to note that they do not cure diabetic retinopathy, and you may need to repeat the procedure in the future.