Diabetic Eye Disease
Diabetic Retinopathy is the result of changes in the blood vessels of the retina caused by diabetes. The retina is the part of the eye that works in the eye the way film works in a camera. In juvenile-onset diabetes it takes at least five years and usually longer to develop diabetic retinopathy, but in older onset diabetes retinopathy may be present at the time of diagnosis. Most patients with diabetic retinopathy will have only mild changes, but because there is risk of more serious vision-threatening changes, the American Diabetes Association recommends that all adult patients with diabetes should be examined at least once a year, even if they are having no visual problems.
There are two types of diabetic retinopathy. The first, and generally milder type is called non-proliferative diabetic retinopathy. In non-proliferative retinopathy the existing blood vessels change, with some becoming narrow and blocked, and others near the blocked vessels becoming larger and developing leaking or oozing areas. This form can cause blurring of the vision, which can get to the point of interfering with demanding visual tasks like reading and driving, but does not cause catastrophic vision loss. It can be treated with laser treatment, which is much more effective if done at an earlier rather than later.
The second type of diabetic retinopathy is called proliferative diabetic retinopathy. In proliferative retinopathy brand new vessels may grow in areas near other blocked vessels. These new vessels (neovascularization- from the Latin words for “new” and “vessels”) are very fragile and can hemorrhage without warning, filling the eye with blood. The scar tissue that forms from these blood clots in the eye can do further damage, possibly causing retinal detachments which can be very difficult to repair. If found early, proliferative retinopathy can be treated with laser treatment and the dangerous new vessels can often (but not always) be eradicated. If laser fails to eradicate the new vessels, or if extensive bleeding occurs before laser treatment can be done, then surgery may be required.
The key to prevention of visual loss is early diagnosis. Treatment before visual loss occurs is much simpler, easier for the patient, and more effective than treatment after visual loss has already occurred. All adult patients with diabetes should be examined at least once a year, and more often if changes are found which are higher risk. Many institutions, such as Boston Medical Center, have walk in Retinal Imaging Programs, where patients can have painless pictures of the inside of the eye done at the same time as they may be visiting their primary care doctors. These images will be interpreted by experience specialists in diabetic retinopathy, and a report made to the primary care doctor. If evidence of diabetic retinopathy is found, the patient will be called for further evaluation.
Good control of blood sugar and blood pressure can decrease the risk of diabetic retinopathy, but even with excellent control some patients may develop eye problems. This is why all patients with diabetes should have evaluation for diabetic retinopathy at least once a year.
