Shedding light on AMD

AMD — that’s short for age-related macular degeneration, quite a long name for a disease associated with aging that gradually destroys the sharp, central vision needed for seeing objects clearly and for doing common daily chores, such as cooking, driving, reading this page (and practically everything we do), according to the National Eye Institute.

A leading cause of blindness among the elderly (read: 50 and up), AMD is enough to scare the living daylights out of anyone. But for those in the dark, let the experts shed light on the issue. As its name suggests, AMD affects the macula, that vital part of our eyes that enable us to see fine detail (yes, even printed matter in small type).

The most common symptom of AMD is blurred vision, which often goes away in brighter light. In some cases, AMD advances so slowly that the person hardly notices any change in his vision. However, in other cases, the disease progresses so fast, leading to loss of vision in both eyes.

A closer look at age-related macular degeneration reveals the presence of yellow deposits under the retina called “drusen.” These yellow deposits are found in patients over the age of 60 and will only reveal themselves during an eye exam with an ophthalmologist. If it’s any consolation, drusen by itself does not usually cause blindness, but take note that an increase in its size and/or number increases a person’s risk of developing advanced AMD, which can lead to loss of vision.

Over time, drusen causes the thinning of the macula, leading to blank areas in the central vision, a condition known as dry AMD. This condition can progress to wet AMD which causes new, weak blood vessels to grow and leak into the back of the eye, causing vision loss. A small — but growing — blind spot appears in the middle of one’s field of vision. In advanced AMD, straight lines appear crooked, resulting in distorted images.

But take heart. All is not lost; there’s hope for those suffering from AMD.

Authorities say we can reduce our risk of acquiring AMD. For starters, if you’re a smoker, you should quit smoking and subscribe to a clean and healthy lifestyle. For another, we should protect our eyes from the harmful rays of the sun and maintain an active lifestyle.

And take this: According to the experts, a healthy diet may not be enough to lower AMD risk.

If you could only see it, your macula appears yellow because the macular pigment contains high levels of carotenoids, the yellow pigments found in many fruits and vegetables. For the most part, the macular pigment consists of lutein and zeaxanthin, two important carotenoids. While the human body doesn’t make its own supply of lutein, zeaxanthin appears to be made in the retina from lutein. Which is why we get our supply of these two carotenoids from our diet. Research shows that the more we eat foods high in lutein, the higher the density of our macular pigment — and vise versa. Low macular pigment density is a risk factor for developing AMD, partly because you have lower levels of antioxidants to protect your macula from free radical damage.

What to do? Dr. Frederick Ferris, director of clinical research at the US National Eye Institute (NEI) and chairman of the Age-Related Eye Disease Study (AREDS), says, “Previous research studies suggest that people who eat a diet rich in green, leafy vegetables have a lower risk of developing AMD. However, the high levels of nutrients that were evaluated in the AREDS are very difficult to achieve with diet alone.”

In a nationwide clinical trial conducted by the NEI and completed in 2001, AREDS found that high levels of antioxidants and zinc significantly reduce the risk of advanced AMD and its associated vision loss. According to the study, people at high risk for developing advanced-stage AMD lowered their risk by about 25 percent when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc. In the same high-risk group — which includes people with intermediate AMD, or advanced AMD in one eye but not the other eye — the nutrients reduced the risk of vision loss caused by advanced AMD by about 19 percent.

“This is an exciting discovery. For people at high risk for developing advanced AMD, these nutrients are the first effective treatment to slow the progression of the disease,” cheerfully notes NEI Director Dr. Paul A. Sieving. “The nutrients are neither a cure for AMD nor will they restore vision already lost from the disease. But they will play a key role in helping people at high risk for developing advanced AMD keep their vision.”

But are you getting enough lutein in your diet? You may want to consider taking lutein in supplement form. In addition to the AREDS formulation of vitamins and minerals, supplements containing lutein — such as Vitalux (multivitamins + minerals) — are available in most pharmacies and leading drugstores. Vitalux (multivitamins plus minerals) is a convenient way to ensure a regular supply of antioxidants and carotenoids needed to protect our eyes from free radical damage.

It’s clear to see why we need to take our eye vitamins.