Frequently Asked Questions

Diabetes

What is diabetic retinopathy?

Introduction

Diabetes affects your body from head to toes, including your eyes. If you have diabetes, your body doesn't use sugar (glucose) properly. Sugar in your blood is vital to your health because it's a main source of energy for your body's cells. But too much sugar in your blood can cause damage throughout your body, including your kidneys, nerves, heart and eyes. The most common and most serious eye complication of diabetes is diabetic retinopathy, which may result in poor vision or even blindness.

Blurred vision and diabetes

Blurred vision can be brought on by rapid fluctuations in blood sugar. Prolonged periods of elevated blood sugar cause sugar and its breakdown products to accumulate in the lens. This accumulation sucks up water and makes the lens swell, shifting your vision towards nearsightedness (distant objects appear blurry). The nearsightedness subsides once your blood sugar is brought under steady control.

Blurred vision can also be caused by macular swelling (edema), regardless of your blood sugar level. This is cause for greater concern because macular edema often develops in people with diabetic retinopathy. The swelling may fluctuate during the day, making your vision get better or worse. If blood vessels in your eye are hemorrhaging, you might notice spots floating in your field of vision. These small spots are often followed within a few days or weeks by larger spots or clouds, which are caused by more marked hemorrhaging.

What is diabetic retinopathy?

Retinopathy is the medical term for damage to the tiny blood vessels (capillaries) that nourish the retina, the tissue at the back of your eye that captures light and relays information to your brain. In some people with diabetic retinopathy, blood vessels may swell and leak fluid. For others, abnormal new blood vessels grow on the surface of the retina. The retina is the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision.

Nearly half of people with known diabetes have some degree of diabetic retinopathy. Initially, most people with diabetic retinopathy experience only mild vision problems; however the condition can worsen and threaten your vision. The threat of blindness is scary, but with early detection and treatment, the risk of severe vision loss from diabetic retinopathy is small. The good news is that you can take steps to protect your sight if you have diabetes: have a yearly dilated eye examination and keep your blood sugar, blood pressure and blood cholesterol under the best possible control.

If you have diabetic retinopathy, at first you may not notice changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.

Visual perception photos above of ocular disease come from the NIH website.