Between 40 to 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy. If you have diabetic retinopathy, your doctor can recommend treatment to help prevent its progression.
Blood vessels damaged from diabetic retinopathy can cause vision loss in two ways.
Fragile, abnormal blood vessels can develop and leak blood into the center of the eye, blurring vision. This is proliferative retinopathy and is the fourth and most advanced stage of the disease.
Fluid can leak into the center of the macula, the part of the eye where sharp, straight-ahead vision occurs. The fluid makes the macula swell, blurring vision. This condition is called macular edema.
Macular edema can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses. About half of the people with proliferative retinopathy also have macular edema.
Diabetic retinopathy often has no early warning signs. Don't wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year to detect the disease before it causes damage to your vision.
In the early stages of diabetic retinopathy, you may not notice any changes in your vision. But if diabetic retinopathy reaches its final stage, proliferative retinopathy, bleeding can occur.
If this happens, at first, you will see a few specks of blood, or spots, floating in your vision. If spots occur, see your eye care professional as soon as possible.
You may need treatment before more serious bleeding or hemorrhages occur causing vision loss or possibly blindness. Hemorrhages tend to happen more than once, often during sleep.
Sometimes the spots clear without treatment, and you will see better. However, bleeding can reoccur and cause severely blurred vision. You need to be examined by your eye care professional at the first sign of blurred vision, before more bleeding occurs.
If left untreated, proliferative retinopathy can cause severe vision loss and even blindness. Also, the earlier you receive treatment, the more likely treatment will be successful.
Diabetic retinopathy and macular edema are detected during a comprehensive eye exam that includes a visual acuity test, dilated eye exam, and tonometry.
A visual acuity test is an eye chart test that measures how well you see at various distances.
In a dilated eye exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of eye problems. After the exam, your close-up vision may remain blurred for several hours.
With tonometry, an instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
During the dilated eye exam, your eye care professional checks your retina for early signs of the disease, including
- leaking blood vessels
- retinal swelling such as macular edema
- pale, fatty deposits on the retina -- signs of leaking blood vessels
- damaged nerve tissue
If your eye care professional believes you need treatment for macular edema, he or she may suggest a fluorescein angiogram. In this test, a special dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your retina.
The test allows your eye care professional to identify any leaking blood vessels and recommend treatment.
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Treatment
Macular edema is treated with laser surgery. This procedure is called focal laser treatment. Your doctor places up to several hundred small laser burns in the areas of the retina around the macula that are leaking.
These burns slow the leakage of fluid and reduce the amount of fluid in the retina. The surgery is usually completed in one session. Further treatment may be needed.
A patient may need focal laser surgery more than once to control the leaking fluid. If you have macular edema in both eyes and require laser surgery, generally only one eye will be treated at a time, usually several weeks apart.
Focal laser treatment stabilizes vision. In fact, focal laser treatment reduces the risk of vision loss by 50 percent. In a small number of cases, if vision is lost, it can be improved. Contact your eye care professional if you have vision loss.
During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular edema. To prevent progression of diabetic retinopathy, people with diabetes should control their levels of blood sugar, blood pressure, and blood cholesterol.
Proliferative retinopathy is treated with laser surgery. This procedure is called scatter laser treatment. Scatter laser treatment helps to shrink the abnormal blood vessels.
Your doctor places 1,000 to 2,000 laser burns in the areas of the retina away from the macula, causing the abnormal blood vessels to shrink.
Because a high number of laser burns are necessary, two or more sessions usually are required to complete treatment.
Although you may notice some loss of your side vision, scatter laser treatment can save the rest of your sight. Scatter laser treatment may slightly reduce your color vision and night vision.
Scatter laser treatment works better before the fragile, new blood vessels have started to bleed. That is why it is important to have regular, comprehensive dilated eye exams. Even if bleeding has started, scatter laser treatment may still be possible, depending on the amount of bleeding.
If the bleeding is severe, you may need a surgical procedure called a vitrectomy. During a vitrectomy, blood is removed from the center of your eye.
Scatter laser treatment and vitrectomy are effective in treating proliferative retinopathy and in reducing vision loss.
People with proliferative retinopathy have less than a 10 percent chance of becoming blind within five years when they get timely and appropriate treatment. Although both treatments have high success rates, they do not cure diabetic retinopathy.
Once you have proliferative retinopathy, you always will be at risk for new bleeding. You may need treatment more than once to protect your sight.
The National Eye Institute, or NEI, is conducting and supporting research that seeks better ways to detect, treat, and prevent vision loss in people with diabetes. This research is conducted through studies in the laboratory and with patients.
For example, researchers are studying drugs that may stop the retina from sending signals to the body to grow new blood vessels. Someday, these drugs may help people control their diabetic retinopathy and reduce the need for laser surgery.
The NEI urges everyone with diabetes to have a comprehensive dilated eye exam at least once a year. If you have diabetic retinopathy, you may need an eye exam more often. People with proliferative retinopathy can reduce their risk of blindness by 90 percent with timely treatment and appropriate follow-up care.
A major study has shown that better control of blood sugar levels slows the onset and progression of retinopathy. The people with diabetes who kept their blood sugar levels as close to normal as possible also had much less kidney and nerve disease. Better control also reduces the need for sight-saving laser surgery.
