People with diabetes are not able to use or store sugar correctly. As a result, sugar can build up in the blood and cause damage throughout the body, including the eyes. Diabetic retinopathy is the most common diabetic eye disease and is the leading cause of blindness in adults in the United States.
What is Diabetic Retinopathy?
The light-sensitive lining inside the back of the eye is called the retina. This is the part of the eye that changes images into nerve signals that are sent to the brain. Tiny blood vessels carry oxygen and nutrients to the retina to keep it healthy and to promote good vision. In people with diabetes, excess sugar in the blood can damage these blood vessels and stop the retina from getting the nutrients it needs. This condition is known as diabetic retinopathy.
The longer a person has diabetes -- either type 1 or type 2–the better the chances this kind of eye damage will occur. There are two types of diabetic retinopathy:
Non-proliferative diabetic retinopathy (NPDR):
This is the first stage of the disease. Blood vessels in the eyes become larger in some places, called microaneurysms. Blood vessels may also become blocked, and small amounts of blood and other fluids may leak into the retina. Eventually, this fluid in the retina can lead to noticeable vision problems.
Proliferative diabetic retinopathy (PDR):
This is the more advanced form of the disease. As blood vessels in the eye are blocked, the retina does not receive enough oxygen. This causes fragile new blood vessels to grow in the retina and the vitreous, which is the gel-like fluid inside the eye. Because these vessels are so fragile, they can leak blood into the vitreous, which clouds the vision. Other possible complications from PDR include a detached retina and glaucoma which causes damage to the optic nerve.
Risk factors for Diabetic Retinopathy
Everyone who has diabetes, either type 1 or type 2, is at risk for diabetic retinopathy. Approximately 40 percent of Americans who have diabetes have some degree of diabetic retinopathy. The longer a person has diabetes, the higher the risk. Other risk factors include:
• Race – African-Americans and Hispanics are at greater risk;
• Medical conditions – High blood pressure and high cholesterol increase your risk; and
• Pregnancy - Pregnant women are at higher risk of developing diabetes, which leads to diabetic retinopathy. Also, women who have gestational diabetes are at higher risk of developing diabetes later in life.
Symptoms of Diabetic Retinopathy
Although not actually a symptom, the most important factor to consider is whether you have diabetes. If you do, don’t wait for symptoms to develop. Regular, annual eye exams where your eye is dilated can diagnose early diabetic retinopathy before you will see any symptoms. Treatment is most effective at this point. Once damage is done to your vision, it typically cannot be reversed. Symptoms during later stages of the disease include:
• Blurred vision and gradual loss of vision;
• Floaters or spots floating in your vision;
• Shadows or missing areas of vision; and
• Difficulty seeing at night.
Diabetic Retinopathy Treatment
If you have diabetes, be sure you get a comprehensive dilated eye exam at least once a year. Do not wait for symptoms to develop. Even people with proliferative retinopathy can reduce their risk of blindness by 95 percent with appropriate and timely treatment. You can help limit your risk by controlling your blood sugar, blood pressure, and cholesterol and by not smoking. If there is damage in your eyes, you may need one of several different surgical procedures to stop or slow the spread of the problem:
• Focal laser photocoagulation – This procedure targets specific small areas where blood or fluids are leaking into the retina. A laser is used to seal the leaks;
• Scatter laser treatment –When blood or fluid are leaking from many locations in the eye, this procedure can be used to shrink abnormal blood vessels. Because a high number of laser burns are necessary, this may require more than one treatment session. This procedure can cause some loss of side vision, and may slightly reduce color vision and night vision. However, it can save the rest of your sight; and
• Vitrectomy – This procedure is used to remove blood or fluids that have leaked into the middle of the eye and are clouding your vision. A small slit is made in the eye which allows the gel-like vitreous to be removed. The vitreous is replaced with a saline solution that serves the same purpose in the eye.
Regardless of whether or not you have any symptoms of diabetic retinopathy, if you have diabetes, be sure to schedule regular appointments with an eye care professional who is trained in treating this disease. Proper care and early detection can protect your eyes and lower your risk of vision damage.
Sources:
American Optometric Association
National Eye Institute
National Institutes of Health – Medline Plus