One common complication of diabetes is retinopathy, a disease of the retina,  the light-sensing region of the inner eye.  The retina acts like a miniature “movie screen” in the back of your eye, on which the images you see are projected. Retinopathy is caused by damage to the blood vessels that supply blood to the retina.

You probably won’t even notice any changes in your vision when diabetic retinopathy first begins. The only way to detect the changes in blood vessels found in the early stages of disease is to have a dilated eye exam by an ophthalmologist or optometrist. And early detection is the key to keeping this disease from interfering with your vision.  Detected early enough, retinopathy can be slowed or stopped altogether.

Retinopathy is more common among people with type 1 diabetes, but people who have had type 2 diabetes can also develop it. There are two major forms of retinopathy. In one type,  called nonproliferative (or background)  retinopathy, blood vessels can close off or weaken. When this happens, they leak blood, fluid, and fat into the eye. Although this can lead to blurry vision, it does not cause blindness, unless there is leakage in the macula, the area of the retina near the optic nerve that is responsible for most of our vision.

Nonproliferative retinopathy can progress to a more serious, although less common, form of eye disease called proliferative retinopathy.

This occurs when new blood vessels sprout, or proliferate, in the retina. This may seem like a good thing, but the new vessels don’t grow in the way they should. Instead, they grow out of control. They are fragile and rupture easily during exercise or even while sleeping, especially if you have high blood pressure. When this happens, blood can leak into the fiuid-filled portion of the eye in front of the retina. This can block the light coming into the eye and impair vision. In addition, scar tissue can form on the retina. The scar tissue often shrinks, and when that happens, it can tear the layers of the retina apart. This damages your eyesight. Glaucoma, or high pressure within the eye,  and cataracts occur more often in people with diabetes. If found early, glaucoma can be treated.

Retinopathy can also cause swelling of the macula of the eye. Because the macula is that central portion of the retina that allows you to see fine detail,  when it swells,  vision can be impaired and blindness can result. This condition is known as macular edema.