Q: What is diabetic retinopathy?
A: Diabetic retinopathy is the most common diabetic eye disease and a leading cause of blindness in American adults. Diabetic retinopathy is a progressive disease that destroys small blood vessels in the retina, eventually causing vision problems. In its most advanced form–proliferative retinopathy–it can cause blindness. According to the National Eye Institute (NEI), between 40 to 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy.
Q: How many people have vision-threatening retinopathy?
A: Nearly all people with type 1 diabetes show some symptoms of diabetic retinopathy, usually after about 20 years of living with diabetes; approximately 20 to 30 percent of them develop proliferative retinopathy, with or without diabetic macular edema. Diabetic macular edema is the leakage of fluid into the center of the eye where sharp, straight-ahead vision occurs. This causes swelling and blurred vision and can happen at any stage of retinopathy, although it is most common in advanced stages. According to the NEI about half of people with the most severe stage of retinopathy also have macular edema. But early control of blood sugar, blood pressure and cholesterol levels, plus timely screening and treatment, can usually prevent serious vision problems. In fact, according to the NEI, people with proliferative retinopathy can reduce their risk of blindness by 95 percent with timely treatment and appropriate follow-up care.
Q: What are the stages of diabetic retinopathy?
A: There are four basic stages.
Stage 1-3: Mild, Moderate and Severe, Nonproliferative, or Background Retinopathy The walls of the retina weaken and develop small, dot-like bulges, or hemorrhages, which may leak fluid or blood into the surrounding tissue. In the earliest stages, vision is rarely affected unless fluid accumulates around the macula (a small area on the retina where vision is sharpest). In this case, the fluid causes the macula to swell, blurring vision (macular edema). As the disease progresses, many more blood vessels are blocked, depriving several areas of the retina with their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment. The earlier the onset of retinopathy is diagnosed the better the opportunity to prevent vision loss.
Stage 4: Proliferative Retinopathy. At this advanced stage, the signals sent by the retina for nourishment trigger the growth of fragile, new blood vessels. These fragile vessels can hemorrhage easily, and blood may leak into the retina and the clear, gel-like vitreous that fills inside of the eye. Unless quickly treated, this can result in spots, floaters, flashes, blurred vision, vision loss, and even temporary blindness. In later phases of the disease, continued abnormal vessel growth and the formation of scar tissue may cause serious problems such as retinal detachment, when the retina pulls away from the back of the eye, and glaucoma, both of which can cause permanent blindness.
Q: What are the symptoms of diabetic retinopathy?
A: Early stages often have no symptoms, but that is when screening and treatment can be most effective. So don’t wait for symptoms, have a comprehensive dilated eye exam from a doctor familiar with diabetic vision problems at least once a year. In more advanced stages when there is bleeding into the eye, you may see a few specks of blood, or spots, floating in your vision. The NEI advises, “If spots occur, see your eye care professional as soon as possible. You may need treatment before more serious bleeding occurs. Hemorrhages tend to happen more than once, often during sleep.”
Q: What symptoms of retinopathy will my doctor look for when I have an eye exam?
A: Among the signs of developing problems are:
- Leaking blood vessels.
- Retinal swelling (macular edema).
- Pale, fatty deposits on the retina–signs of leaking blood vessels.
- Damaged nerve tissue.
- Any changes to the blood vessels.
Q: Does diabetic retinopathy run in families?
A: Diabetic retinopathy seems to have a genetic component. That is, a patient’s risk of developing eye disease is greater if they have a close relative who has already been diagnosed with diabetic retinopathy. Discovering the genes that predispose a person to this complication could lead researchers to new molecular targets for drug development to combat it.
Q: I am planning to become pregnant, how does that affect my eye health?
A: Pregnant women who are diabetic are especially vulnerable to diabetic retinopathy and should have eye exams every trimester.
Q: What are the treatment options?
A: During the first three stages of diabetic retinopathy, treatment is generally not done, unless you have macular edema. Then focal laser therapy is used.
Currently there is a treatment approved for wet age-related macular edema and retinal vein occlusion, called Lucentis (ranibizumab, a monoclonal antibody). Current studies of its effect on diabetic retinopathy indicate that it may reduce edema and retinal thickness and may actually improve vision. One large study found it was effective for about 50% of patients.
If you develop proliferative retinopathy, so-called scatter laser treatment can shrink the abnormal blood vessels. The procedure can save your sight, although it may reduce your peripheral and night vision. When bleeding is severe, a vitrectomy, which removes blood from the center of the eye, may also be done.
Q: Will treatment cure diabetic retinopathy?
A: Your vision may improve with treatment, but today we do not have a cure. Once you have the disease you will need faithful monitoring of your eyes, and perhaps repeat treatment. But with good medical attention and control of glucose, blood pressure and cholesterol levels, you may preserve your vision to a significant extent.