Seeking a Better Way to Fight Eye Disease

Adding components found in fish oil doesn't improve a pill that may help to slow down a blinding eye disease. But a new study found potential benefit in tweaking the pills' contents in other ways. The study included about 1,600 people. All had macular degeneration in at least one eye. A supplement containing vitamins C and E, beta-carotene, copper and zinc has been shown to slow how rapidly the disease gets worse. The new study assigned people to receive those pills plus one of four other pills. They contained the vegetable pigments lutein and zeaxanthin, the omega-3 fatty acids DHA and EPA, all four, or none of the four (placebo). Overall, none of these extra pills helped to slow the disease. But some people received the original formula pill in a version that left out beta-carotene. People who got this version of the original formula seemed to gain benefit from taking lutein and zeaxanthin. Leaving out beta-carotene did not reduce the benefit of the original pills for anyone. Beta-carotene may increase lung cancer risk in smokers. The authors said more research is needed. The Journal of the American Medical Association published the study online. USA Today wrote about it May 6.

By Lori Wiviott Tishler, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

Macular degeneration runs in my family. One of my elderly aunts was blind before she died. My grandfather struggled with his vision. It was harder for him to be unable to see well than it was for him to be terribly limited by a heart condition. He couldn't move easily, and his vision restricted him further from exploring the world through reading, watching TV or driving.

Macular degeneration is an eye condition that affects our central visual area, called the macula. It's also called age-related macular degeneration or AMD. People with macular degeneration gradually lose their vision right in the middle of their eyes. They find that they cannot see well straight ahead and cannot see fine details.

Severely affected people can't drive, read or do crafts. AMD is the cause of half of the blindness in the United States. It is the leading cause of blindness in the developed world.

Wet and dry macular degeneration are the two types of this disease. The wet kind gets worse faster than the dry kind does. The dry kind is more common. There are some experimental treatments for wet AMD, but no good treatments for dry AMD. However, a specific combination of vitamins, discussed below, may help to slow down the disease.

This latest news relates to a study called the Age Related Eye Disease Study, or AREDS. Previous research based on this study has found that certain vitamins and minerals may help prevent macular degeneration from developing or getting worse. They include vitamins C and E, beta-carotene, zinc and copper.

The new study added different combinations of supplements to the original formula of proven vitamins. Researchers wanted to see if other supplements would be of further benefit. They tested four groups. All four received the original formula.

• One group also got lutein and zeaxanthin. These are plant-derived antioxidants. Lutein is found in leafy green vegetables like kale and spinach. Zeaxanthin is related to vitamin A. It is responsible for the colors of paprika, corn and saffron.
• A second group also got DHA and EPA, omega-3 fatty acids found in fish oils.
• A third group also got lutein, zeaxanthin, DHA and EPA.
• People in the fourth group got no extra supplements. They took placebo (fake) pills.

The study, unfortunately, found that none of the extra supplements further delayed or decreased vision loss.

Some people received the original formula without beta-carotene, which has been linked with higher lung cancer risk in smokers. The formula appeared to be just as effective without it.

Based on their analysis, the authors hope that looking further at the lutein and zeaxanthin groups will lead to a role for these supplements. In these small groups, people who received the original formula without beta-carotene did better than those whose pills included it. People who had very low levels of lutein and zeaxanthin in their diets also did better with these supplements than those who got more from their diets.

What Changes Can I Make Now?

Macular degeneration is more common in smokers, whites and people who have a family history of the condition. If you are over 50 and in a high-risk group, it's reasonable to see an eye doctor for an exam. At this age, it is also a good idea to be checked for other eye diseases, such as glaucoma or cataracts. If you have diabetes, you should see an eye doctor every year.

Don't wait until you have trouble with your vision. At this point, we cannot restore vision, so preventing any loss is key to maintaining your eyesight.

If your doctor recommends it, you might consider taking the AREDS vitamin preparation. It works best for certain groups of people, so definitely talk to a doctor before deciding to take these supplements. Also, be sure to eat your leafy green veggies.

If you are already having problems with your vision, don't despair and don't delay. Your eye doctor can help you find a low-vision specialist and some visual rehabilitation. These steps can help you make the best of what you have and continue to enjoy a rich, full life.

What Can I Expect Looking to the Future?

This work really shows the benefit of large research studies. These studies are able to answer complicated questions and point us in good directions for future learning. Great strides have been made in macular degeneration during the last several years. I hope they will continue in both treatment and prevention.