If you have diabetes, your body can't use or store sugar properly. When blood sugar gets too high, it can damage the blood vessels in your eyes. This damage may lead to diabetic retinopathy. In fact, the longer someone has diabetes, the more likely he is to have retinopathy. In later stages, the disease may lead to new blood vessel growth over the retina. The new blood vessels can cause scar tissue to develop, which can pull the retina away from the back of the eye. This is known as retinal detachment, and it can lead to blindness if untreated. In addition, abnormal blood vessels can grow on the iris, which can lead to glaucoma.

Treatment
Diabetic retinopathy can be treated with laser photocoagulation to seal off leaking blood vessels and destroy new growth. Laser photocoagulation doesn't cause pain, because the retina does not contain nerve endings.

In some patients, blood leaks into the vitreous humor and clouds vision. At that time, we may choose to simply wait to see if the clouding will dissipate on its own, a period called "watchful waiting." A procedure called a vitrectomy removes blood that has leaked into the vitreous humor. The body gradually replaces lost vitreous humor, and vision usually improves.

If diabetic retinopathy has caused your body to form a cataract, it can be corrected surgically. Small studies using investigational treatments for diabetic retinopathy have demonstrated significant vision improvement for individuals who are in early stages of the disease. Two treatments that are closely related, Lucentis and Avastin, may be able to stop or reverse vision loss, similar to very promising results that have been reported when the two drugs have been used as treatments for macular degeneration.
Early detection is why it is so important for diabetics to have a dilated eye exam at least once a year.