Diabetic retinopathy is damage to the eye's retina that occurs with long-term diabetes.

See also:

• Type 1 diabetes
• Type 2 diabetes

Diabetic retinopathy is caused by damage 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 that are sent to the brain.

There are two types, or stages of retinopathy: non-proliferative or proliferative.

• Non-proliferative diabetic retinopathy develops first. Blood vessels in the eye become larger in certain spots (called microaneurysms). Blood vessels may also become blocked. There may be small amounts of bleeding (retinal hemorrhages), and fluid may leak into the retina. This can lead to noticeable problems with your eyesight.
• Proliferative retinopathy is the more advanced and severe form of the disease. New blood vessels start to grow in the eye. These new vessels are fragile and can bleed (hemorrhage). Small scars develop, both on the retina and in other parts of the eye (the vitreous). The end result is vision loss, as well as other problems.

Other problems that may develop are:

• Macular edema -- the macula is the area of the retina that provides sharp vision straight in front of you. If fluid leaks into this area, your vision becomes more blurry.
• Retinal detachment -- scarring may cause part of the retina to pull away from the back of your eyeball.
• Glaucoma -- increased pressure in the eye is called glaucoma. If not treated, it can lead to blindness.
• Cataracts

Diabetic retinopathy is the leading cause of blindness in working-age Americans. People with both type 1 diabetes and type 2 diabetes are at risk for this condition.

Having more severe diabetes for a longer period of time increases the chance of getting retinopathy. Retinopathy is also more likely to occur earlier and be more severe if your diabetes has been poorly controlled. Almost everyone who has had diabetes for more than 30 years will show signs of diabetic retinopathy.