Diabetes and Retinopathy (Eye Complications)

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Diabetes is a disease that affects the body's ability to produce or respond to insulin, a hormone that allows blood glucose (blood sugar) to enter the cells of the body and be used for energy. Diabetes falls into two main categories: type 1, which usually occurs during childhood or adolescence, and type 2, the most common form of the disease, which usually occurs after age 45, but is increasingly being diagnosed in children and adolescents.

Diabetes is the fifth-deadliest disease in the United States, and it has no cure. The total annual economic cost of diabetes in 2002 was estimated to be $132 billion, or one out of every 10 health care dollars spent in the United States.

What vision problems can be caused by diabetes?

Vision impairment is a frequent complication of diabetes, for both type 1 and type 2.

• The major cause of blindness in people with diabetes is diabetic retinopathy. Diabetic retinopathy is a term used for all the abnormalities of the small blood vessels of the retina caused by diabetes, such as weakening of blood vessel walls or leakage from blood vessels. Retinopathy progresses from non-proliferative or background retinopathy to proliferative retinopathy.

Non-proliferative retinopathy is a common, usually mild form that generally does not interfere with vision. Abnormalities are limited to the retina and usually will only interfere with vision if it involves the macula, the area on the retina that gives us the sharpest vision. If left untreated it can progress to proliferative retinopathy.

Proliferative retinopathy, the more serious form, occurs when new blood vessels branch out or proliferate in and around the retina. It can cause bleeding into the fluid-filled center of the eye or swelling of the retina, and lead to blindness.

• Nearly all patients who have type 1 diabetes for about 20 years will have evidence of diabetic retinopathy.



• Up to 21% of people with type 2 diabetes have retinopathy when they are first diagnosed with diabetes, and most will eventually develop some degree of retinopathy.



• In the United States, diabetes is responsible for 8% of legal blindness, making it the leading cause of new cases of blindness in adults 20-74 years of age. Each year, between 12,000 to 24,000 people lose their sight because of diabetes.



• Glaucoma, cataract, and corneal disease are more common in people with diabetes and contribute to the high rate of blindness.

Can diabetes-related vision problems be prevented?

The key to preventing diabetes-related eye problems is good control of blood glucose levels, a healthy diet and good eye care.

• The Diabetes Control and Complications Trial (DCCT), a 10-year study which ended in June 1993, proved among type 1 patients that improved blood glucose control prevents or delays diabetic retinopathy. Therapy that keeps blood sugar levels as close to normal as possible reduced damage to the eyes by 76%. (New England Journal of Medicine, September 30, 1993)



• Because a person with diabetes can have retinopathy and not know it, a regular checkup with an eye care professional is essential. Regular checkups with an eye doctor can detect retinopathy early and possibly prevent blindness.

What should people with diabetes do?

• People with type 1 diabetes should see their eye care professional annually for a dilated eye examination beginning five years after the onset of diabetes. Women with type 1 who are pregnant should have a comprehensive eye examination in the first trimester and close follow-up throughout pregnancy.



• People with type 2 diabetes should see their eye care professional for a dilated eye examination shortly after diagnosis of diabetes and annually thereafter.

What is needed?

In ideal circumstances, people with diabetes will have their disease under good control and be monitored frequently by a health care team knowledgeable in the care of diabetes.

• Health care team education is vital. Because people with diabetes have a multi-system chronic disease, they are best monitored and managed by highly skilled health care professionals trained with the latest information on diabetes to help ensure early detection and appropriate treatment of the serious complications of the disease. A team approach to treating and monitoring this disease serves the best interests of the patient.



• Patient education is critical. People with diabetes can reduce their risk for complications if they are educated about their disease, learn and practice the skills necessary to better control their blood glucose levels, as well as blood pressure and cholesterol levels, and receive regular checkups from their health care team. Smokers should stop smoking, and overweight people with diabetes should develop a moderate diet and exercise regimen under the guidance of a health care provider to help them achieve a healthy weight.



• Reimbursement for eye examinations and diabetes education is essential. To reduce the cases of blindness due to diabetes, early detection is important. Patient education, health care team education, and affordable eye care can make this possible.