Diabetes can harm the eyes. It can damage the small blood vessels in the retina, the back part of your eye. This condition is called diabetic retinopathy.
Diabetes also increases the chance of having glaucoma, cataracts, and other eye problems.
Diabetic retinopathy is caused by damage from diabetes to blood vessels of the retina. The retina is the layer of tissue at the back of the inner eye. It changes light and images that enter the eye into nerve signals, which are sent to the brain.
Diabetic retinopathy is a main cause of decreased vision or blindness in Americans ages 20 to 74 years. People with type 1 or type 2 diabetes are at risk for this condition.
The chance of developing retinopathy and having a more severe form is higher when:
If you already have damage to the blood vessels in your eye, some types of exercise can make the problem worse. Check with your health care provider before starting an exercise program.
Other eye problems that can occur in people with diabetes include:
High blood sugar or rapid changes in blood sugar level often cause blurred vision. This is because the lens in the middle of the eye cannot change shape when it has too much sugar and water in the lens. This is not the same problem as diabetic retinopathy.
Most often, diabetic retinopathy has no symptoms until the damage to your eyes is severe. This is because damage to much of the retina can occur before your vision is affected.
Symptoms of diabetic retinopathy include:
Many people with early diabetic retinopathy have no symptoms before bleeding occurs in the eye. This is why everyone with diabetes should have regular eye exams.
Your eye doctor will examine your eyes. You may first be asked to read an eye chart. Then you will receive eye drops to widen the pupils of your eyes. Tests you may have involve:
If you have the early stage of diabetic retinopathy (nonproliferative), the eye doctor may see:
If you have advanced retinopathy (proliferative), the eye doctor may see:
This exam is different from going to the eye doctor (optometrist) to have your vision checked and to see whether you need new glasses. If you notice a change in vision and see an optometrist, make sure you tell the optometrist that you have diabetes.
People with early diabetic retinopathy may not need treatment. But they should be closely followed by an eye doctor who is trained to treat diabetic eye diseases.
Once your eye doctor notices new blood vessels growing in your retina (neovascularization) or you develop macular edema, treatment is usually needed.
Eye surgery is the main treatment for diabetic retinopathy.
Medicines that are injected into the eyeball may help prevent abnormal blood vessels from growing.
Follow your eye doctor's advice on how to protect your vision. Have eye exams as often as recommended, usually once every 1 to 2 years.
If you have diabetes and your blood sugar has been very high, your doctor will give you new medicines to lower your blood sugar level. If you have diabetic retinopathy, your vision can get worse for a short time when you begin taking medicine that quickly improves your blood sugar level.
Many resources can help you understand more about diabetes. You can also learn ways to manage your diabetic retinopathy.
Managing your diabetes may help slow diabetic retinopathy and other eye problems. Control your blood sugar (glucose) level by:
Treatments can reduce vision loss. They do not cure diabetic retinopathy or reverse the changes that have already occurred.
Diabetic eye disease can lead to reduced vision and blindness.
Call for an appointment with an eye doctor (ophthalmologist) if you have diabetes and you have not seen an ophthalmologist in the past year.
Call your doctor if any of the following symptoms are new or are becoming worse:
Good control of blood sugar, blood pressure, and cholesterol are very important for preventing diabetic retinopathy.
DO NOT smoke. If you need help quitting, ask your provider.
Women with diabetes who become pregnant should have more frequent eye exams during pregnancy and for a year after delivery.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.