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What is diabetic retinopathy?
- Diabetic retinopathy is a potentially serious eye disease caused by diabetes. It affects the retina - the light-sensitive tissue at the back of the eye that transmits visual messages to the brain. Damage to this delicate tissue may result in visual impairment or blindness.
- Diabetic retinopathy begins with a slight deterioration in the small blood vessels of the retina. Portions of the vessel walls balloon outward and fluid starts to leak from the vessels into the surrounding retinal tissue.
- Subsequent developments (vascular proliferation, bleeding, retinal scarring, detachment, etc.) are all either directly or indirectly due to the retinal ischemia that results from vascular damage.
- Generally, these initial changes in the retina cause no visual symptoms. However, they can be detected by an eye specialist who is trained to recognize subtle signs of retinal disease.
- In many people with diabetic retinopathy, the disease remains mild and never causes visual problems. But in some individuals, continued leakage from the retinal blood vessels leads to MACULAR EDEMA.
- This is a build-up of fluid in the macula - the part of the retina responsible for the sharp, clear vision used in reading and driving.
- When critical areas of the macula become swollen with excess fluid, vision may be so badly blurred that these activities become difficult or impossible.
- Some people with diabetes develop an even more sight-threatening condition called PROLIFERATIVE RETINOPATHY.
- It may occur in people who have macular edema, but also can develop in those who don't. In proliferative retinopathy, abnormal new blood vessels grow on the surface of the retina.
- These fragile new vessels can easily rupture and bleed into the middle of the eye, blocking vision. Scar tissue also may form near the retina, ultimately detaching it from the back of the eye.
- Severe visual loss, even permanent blindness, may result. But this happens in only a small minority of people with diabetes.
- American Diabetes Association
1660 Duke St.
Alexandria, VA 22314
- Juvenile Diabetes Foundation
432 Park Ave. South, 16th floor
New York, NY 10016
- Wisconsin Chronic Disease Prevention Program
1 West Wilson St.
PO Box 2659
Madison, WI 53701-2659
Answers to frequently asked questions
Below are answers to frequently asked questions about diabetic retinopathy.
Why is it important to know how diabetes affects the eyes?
- If you are among the 10 million people in the United States who have diabetes - or if someone close to you has this disease - you should know that diabetes can affect the eyes and cause visual impairment.
- Fortunately, there are ways to prevent or lessen the eye damage caused by diabetes. That is why it is so important for people with this disease to have a professional eye examination as soon as their diabetes is diagnosed, and at least once a year thereafter.
- Regular eye examinations are especially important for people who have had diabetes 5 years or longer, for those who have difficulty controlling the level of sugar in their blood, and for diabetic women who are pregnant.
- All of these people are at increased risk for diabetes-associated eye problems.
How many diabetics are affected?
- Approximately 40 percent of all people with diabetes have at least mild signs of diabetic retinopathy. About 3 percent have suffered severe visual loss because of this disease.
- In general, the longer one has had diabetes, the greater one's chances of developing diabetic retinopathy.
What are the symptoms of diabetic retinopathy?
- As already indicated, diabetic retinopathy generally causes no symptoms in its earliest stages. For the person who develops macular edema, blurring of vision may provide a clue that something is wrong.
- But proliferative retinopathy can progress a long way without any warning signs. That is why a person with diabetes should make regular visits to an eye specialist, so any eye problems can be detected and treated if necessary.
How is diabetic retinopathy treated?
- Recently, scientists have found that laser treatment can prevent visual loss in many people with diabetic macular edema. In this treatment, called photocoagulation, powerful beams of light from a laser are aimed at leaking retinal blood vessels in the macula.
- The goal of treatment is to seal the vessels and prevent further leakage. In many patients, this treatment halts the decline in vision or even reverses it.
Research also has shown that laser photocoagulation can dramatically reduce the risk of blindness in people who have proliferative retinopathy.
- For these patients, the laser is used in a different way: It is not directed at the macula but is aimed at hundreds of spots in other parts of the retina.
- The purpose of the treatment is to destroy diseased tissue and stop the retinopathy from getting worse. In fact, the treatment can reduce the risk of severe visual loss by 60 percent.
- The studies which proved the value of laser treatment for people with diabetic retinopathy were supported by the National Eye Institute. It is part of the National Institutes of Health, a component of the U.S. Department of Health and Human Services.
What research is being done on diabetic retinopathy?
- The National Eye Institute is supporting a nationwide study to determine whether photocoagulation - used alone or in combination with aspirin - can benefit people who are still in the early stages of diabetic retinopathy.
- Almost 4,000 patients are enrolled in this 5-year clinical trial. It already has proven the value of photocoagulation for macular edema (see "How is diabetic retinopathy treated?"), and is expected to yield further valuable findings in the future.
- Another clinical trial sponsored by the Institute and Pfizer, Inc., is evaluating a new drug called sorbinil to see if it can prevent eye and nerve damage in people with diabetes.
- In addition to these clinical trials, the Institute is supporting an extensive program of research on the causes, detection, and treatment of diabetic retinopathy.
Who can refer you to an eye care specialist?
- If you know you have diabetes, you are probably under the care of a physician who can refer you to an eye doctor for regular examinations and treatment, if needed.
- You may also request the name of an appropriate eye doctor from eye care centers affiliated with academic institutions, from a hospital, or from a diabetes clinic at a medical center.
What help is available to the person who has already lost vision from diabetic retinopathy?
- There are many useful devices that can help a partially sighted person to make the most of his or her remaining vision. Called low vision aids, these devices have special lenses or electronic systems that produce enlarged images of nearby objects.
- The Vision Forward Association has a low vision therapist on staff that can help identify and train individuals with the low vision aids. Additionally, equipment adapted with voice or tactual output can be purchased at the Vision Forward Store. For more information, call 414-615-0124.