March 2, 2011

March is AMD Awareness Month

By Michael Howcroft, M.D.
Eye Surgeons Associates

Age- Related Macular Degeneration (AMD) Update

Advanced AMD, in either wet or dry form, can destroy the detailed, central vision we need to recognize faces, read, drive, and enjoy daily life. It is a major cause of vision loss in the 50 plus age group in the United States. While ophthalmologists can turn to several medications for patients with vision-threatening wet age-related macular degeneration (AMD), there are currently no FDA-approved treatments for advanced dry AMD, the more common form.

There are things however that you can do to minimize your risk, and there is some promising research. High blood pressure, hyperlipidemia (high serum cholesterol or triglycerides), smoking and obesity are risk factors that can be controlled and/or eliminated. In the same way that you protect your skin from the sun with sun block, you should also protect your eyes from bright sunlight with dark sunglasses.

While special eye supplements have never been shown to prevent AMD, a large clinical trial called AREDS found that in people with AMD it can help slow vision loss in one out of four cases. A large clinical trial conducted by the National Eye Institute demonstrated the protective effect of high dose anti-oxidants on the progression of moderate to severe AMD. These anti-oxidants include vitamins A, C, E and zinc.

Eating fish may also reduce the risk of AMD. Research has found that those who ate the most marine fats (omega-3s) had a reduced risk of advanced AMD. And if you have dry eyes, some researchers think that omega-3s may also improve symptoms.

More recently, the National Institute of Health is currently conducting AREDS 2. The main objective is to determine if oral supplementation with xanthophylls and/or omega-3 acids will decrease the risk of progression to advanced AMD as the original AREDS formulation did by 25 percent.

It makes sense to eat a balanced diet with healthy portions of fresh fruit and vegetables that contain anti-oxidant vitamins and the heart-healthy omega-3s. The U.S. Department of Health and Human Services program of disease prevention and health promotion goals for the nation found that fewer than 10 percent of the population eats five fruits and vegetables a day making vitamin supplementation necessary for most people. Omega-3s have been found to be heart healthy, so while we’re waiting for these studies, for most of us, eating more of these items or taking supplements won’t hurt and may help us in many ways – healthier eyes and lives.

There is active research into effective treatments for dry macular degeneration and there are a number of medications that are being investigated in clinical trials.

One study is working on a phase-two clinical trial of an arthritis drug, fenretinide, which is a synthetic derivative of vitamin A. Risk of developing wet AMD decreased almost two-fold in dry AMD patients who took the medication. In the advanced wet form abnormal new blood vessels develop under the retina, then bleed or leak fluid and form scars. Advanced dry AMD sometimes abruptly converts to the wet form. Fenretinide has strong anti-inflammatory properties, inhibits abnormal blood vessel growth and reduces vitamin-A derived toxins, three key AMD disease mechanisms.

Hopefully, this study and other research will help give us tools to fight this devastating condition while we continue to look for ways to cure AMD. It is expected that FDA-approved treatments for dry AMD will be available within two to three years or less.

Michael Howcroft, M.D., of Eye Surgeons Associates is board certified and fellowship trained in vitreoretinal surgery. His specialty interests include the medical and surgical treatment of age-related macular degeneration, diabetic retinopathy, retinal vascular disease, retinal detachment, ocular trauma and ophthalmic ultrasound. For more information visit: www.esaeyecare.com.