Your risk of developing diabetic retinopathy depends largely on two factors: how long you have had diabetes and whether or not you have kept good control of your blood sugar.

You can control some risk factors that may increase your risk for diabetic retinopathy and its complications. Risk factors that you can control include:

• Pregnancy. Women who have diabetes are at increased risk of developing retinopathy during pregnancy. In about half of women who already have retinopathy when they become pregnant, the condition becomes worse during pregnancy.¹
• Consistently high blood sugar. Long-term studies show that high blood sugar levels increase your risk of retinopathy. Keeping your blood sugar level near normal can reduce your risk of diabetic retinopathy and can slow the progression of the disease if it has already developed.^{2, 3}
• High blood pressure. In general, people with diabetes who also have high blood pressure are more likely to develop complications that affect the blood vessels in the body, including those in the eyes. The results of long-term studies suggest that retinopathy is more likely to progress to the severe (proliferative) form of the disease and to macular edema in people who have high blood pressure.^{4, 1}
• Delayed diagnosis and treatment. Getting yearly eye exams cannot prevent retinopathy, but it may reduce your risk of severe vision loss from complications of retinopathy. Early treatment can prevent vision loss and delay the progression of the disease.
• High cholesterol. Some studies suggest that having a high cholesterol level increases the risk of retinopathy. But it is not known whether reducing high cholesterol levels affects the progression of retinopathy over time.¹
• Smoking. Although smoking has not been proven to increase the risk of retinopathy, smoking does increase your blood pressure and may make many of the other health problems faced by people with diabetes worse, including disease of the small blood vessels.

If you have type 2 diabetes and use the medicine rosiglitazone (Avandia, Avandamet, Avandaryl) to treat your diabetes, you may have a higher risk for problems with the center of the retina (the macula). The U.S. Food and Drug Administration (FDA) and the makers of the drug have warned that taking this medicine could cause swelling in the macula, which is called macular edema.