Catch vision problems early
Diabetic retinopathy is a common cause for vision problems. In people who have diabetes, elevated blood glucose damages the small blood vessels in the retina, the network of nerves in the innermost eye that sends "snapshots" of images to the optic nerve and on to the brain.
It's estimated that more than 4 million Americans suffer from diabetic retinopathy, usually due to poor control of blood glucose. People with type 1 diabetes are more likely to have severe, vision-threatening retinopathy.
The early stages of retinopathy typically come with no symptoms. Blood vessels in the retina develop weaknesses that may lead to leaking of blood and other fluids into the retinal tissue, notes Lloyd Paul Aiello, M.D., Ph.D., professor of ophthalmology at Harvard Medical School and director of the Beetham Eye Institute at the Joslin Diabetes Center. These changes can progress to more serious microvascular abnormalities, says Dr. Aiello, and lead to proliferative retinopathy, which is characterized by the growth of undesirable blood vessels in the back of the retina.
These new blood vessels can rupture and cause bleeding into the vitreous humor (a thick, gel-like substance that fills the eyeball behind the lens), or cause the retina to detach from the back of the eye. At any point in the development of retinopathy, a condition known as macular edema can occur, in which leakage from retinal vessels causes swelling around the macula (the center of the retina, responsible for central vision, color perception and detailed vision), which leads to blurred vision.
"Diabetic retinopathy is the leading cause of new blindness in working-age Americans," says Steven Schwartz, M.D., director of the Diabetic Eye Disease and Retinal Vascular Center at the University of California, Los Angeles, Jules Stein Eye Institute. "And the vision loss is often completely preventable." An annual examination by an ophthalmologist (not an optometrist) with experience caring for diabetic retinopathy is crucial, says Dr. Schwartz: In its early, symptomless stages, retinopathy can only be caught by a doctor's careful examination.
Patients with type 1 diabetes should see an ophthalmologist within five years of their diagnosis—that's the amount of time it typically can take for retinopathy to affect someone whose pancreas has stopped producing insulin. On the other hand, those who have been diagnosed with type 2 should see an ophthalmologist immediately, because it's possible that asymptomatic retinopathy has been developing for some time.
From our sister publication, Diabetes Focus (Spring 2011)