Recent Breakthroughs Can Prevent Serious Vision Problems
When was the last time you had your eyes examined? If you're drawing a blank, it's time to make an appointment with an ophthalmologistespecially if you have diabetes. You could have diabetic eye disease and not even know it.
A study from Johns Hopkins University School of Medicine found that only six out of 10 patients with eye damage due to diabetes had had their vision checked within the previous year. Just half of them had even been made aware of the link between diabetes and vision loss.
Unfortunately, eye disease, specifically diabetic retinopathy "may develop in ways that go unrecognized because it may not affect vision until it's at a very advanced stage," says Jonathan Sears, M.D., a retinal specialist at the Cleveland Clinic's Cole Eye Institute. Between 40 and 45 percent of Americans with diabetes have diabetic retinopathydamage to the blood vessels in the retina, which is a leading cause of blindness.
There are several forms of the disease. With nonproliferative retinopathy, capillaries in the back of the eye balloon and form pouches. As the disease advances, blood vessels become blocked.
In patients with macular edema, capillary walls break down and fluids can leak into the macula, the part of the eye responsible for focusing. Over time, this swelling can cause blurred vision and eventually blindness.
The most serious form is proliferative retinopathy, in which blood vessels in the retina sustain so much damage they close off completely. In response to the lack of nourishment, the retina signals the eye to grow new blood vessels. "The problem is that these new fragile blood vessels have less stable walls and are more prone to bleeding," says Robert Cohen, M.D., professor of medicine at the University of Cincinnati Medical Center. "It's the bleeding from retinopathy that is the biggest threat to vision."
The new blood vessels can also cause scar tissue to grow. Over time, the scar tissue contracts and can pull the retina out of place, causing it to detach, Cohen says. In some cases, blindness can result.
See Your Ophthalmologist
The American Diabetes Association recommends that people with diabetes get their vision tested by an ophthalmologist every year to check for diabetic retinopathy as well as other types of eye disease. Diabetes can affect your eyes in several ways.
In the early stages of the disease, you can experience blurred vision, caused by fluid leaking into the lens of the eye as a result of high glucose levels; this causes the lens to swell and changes its ability to focus properly. Blurred vision can also occur early in insulin treatment when fluctuating blood glucose levels cause fluids to shift in and out of the eye. Your vision should improve when glucose levels are brought under control and stabilized.
If you have diabetes, you have a 40 percent greater risk of glaucoma, a disease in which pressure builds up in the eye, pinching the blood vessels that carry blood to the retina and optic nerve. You are also 60 percent more likely to develop cataracts, which cause the eye's lens to become cloudy, blocking light.
If your eye exam turns up any sort of diabetic retinopathy, you'll need to see a retinal specialist every six months. "Frequent visits with eye doctors are a good way to help people with diabetes maintain their sight," Sears says.
Know Your Options
Fortunately, treatment for diabetic retinopathy has improved significantly in recent years. Proliferative retinopathy can be combated with scatter laser treatment. During this procedure, doctors make hundreds of burns on the retina to seal and shrink the abnormal blood vessels, reducing the risk of blindness from bleeding and detachment. Laser treatment and good follow-up care can reduce the risk of blindness by 90 percent, according to the National Eye Institute (NEI).
Nonproliferative retinopathy may be accompanied by edema, or swelling of central retinal tissues. This condition can be treated with focal laser therapy, which involves making small laser burns to the affected areas.
A medical treatment, called anti-VEGF (anti-vascular endothelial growth factor), is delivered via injection directly into the eye. "Anti-VEGF treatment has revolutionized eye care for nonproliferative disease much like laser therapy revolutionized care for proliferative disease," says Sears.
Macular edema can also be treated with focal laser therapy or anti-VEGF medications to slow the leakage of fluid into the macula.
Think Prevention First
Of course, it's always best to prevent eye problems from developing in the first place, experts say, and controlling blood glucose is key. "Good glucose control can slow the onset of eye disease," says Sears. That means taking your prescribed medications for diabetes and other conditions, such as high blood pressure and elevated cholesterol, and following your doctor's advice on eating healthily and getting enough physical activity. "Exercising regularly is the best way to maintain good blood sugar," Sears says.
Tobacco harms small blood vessels, so if you smoke or chew tobacco, it's important to make an effort to quit.
In a landmark research study conducted by the National Institute of Diabetes and Digestive and Kidney Disease, people who kept their hemoglobin A1C levelsyour average blood glucose reading over two or three monthsas close as possible to normal (6 percent or less) reduced the risk of developing diabetic retinopathy by 76 percent. Intensive management of blood sugar slowed the progression of the disease by 54 percent. "The hard work of managing blood sugar really does pay off," says Sears.
Source: from our sister publication Diabetes Focus Fall 2014