Macular degeneration, an eye disorder that damages the macula, which is the part of the retina responsible for sharp vision in the center of the visual field, impairs the ability to see things clearly and to perform tasks such as reading that require sharp vision. The National Library of Medicine reports that macular degeneration is a major cause of vision loss in Americans over the age of 60. Although there is no cure, several treatments may help, including surgery, drugs and use of a vitamin and mineral supplement containing zinc.
Types of Macular Degeneration
There are two types of macular degeneration, called dry and wet. Dry macular degeneration is more common, affecting 85 percent of those with the disease. The dry type causes gradual vision loss in either one or both eyes. Wet macular degeneration is more severe and may cause a sudden loss of vision in the center of the visual field. Often, the dry type occurs first, followed by progression to the wet type. Risk factors for macular degeneration include age, family history of the disorder, high cholesterol and obesity. Women are more at risk than men, and cigarette smokers are at greater risk.
Zinc
Zinc is a dietary mineral that helps the immune system fight off bacteria and viruses, according to the Office of Dietary Supplements. Cells use zinc to manufacture proteins and DNA, making it essential for growth and development. Zinc supports growth of skin during healing of wounds and it is necessary for maintenance of the sense of smell and taste. An adult women needs a minimum of 8 mg of zinc daily and an adult man needs 11 mg.
The Age-Related Eye Disease Study
The National Eye Institute conducted a 10-year clinical trial called the Age-Related Eye Disease Study or AREDS. This trial tested whether a combination of antioxidants and zinc would lower the risk of macular degeneration and other eye disorders that strike older people. The trial involved over 4,000 patients, some of whom consumed antioxidant vitamins, vitamin C 500 mg and vitamin E 400 IU, and 15 mg of beta-carotene and 80 mg of zinc oxide daily. The dose was taken with food, half in the morning and half later in the day.
Findings
Dr. Emily Chew, an ophthalmologist writing in "Dietary Supplement Use in the Elderly for the National Eye Institute," reports that daily doses of the combination of vitamins and zinc lowered the incidence of vision loss by 25 percent for people who had a significant risk of developing macular degeneration or other age-related eye diseases. The study also suggested that taking the vitamin-zinc combination may reduce the degree of vision loss for people who develop the disease. Chew states that "the public health impact of the AREDS supplements is enormous."
Recommendations
The National Eye Institute recommends that anyone who has intermediate macular degeneration in one or both eyes should take the vitamin and zinc formula. It also may help people who already have advanced disease and it may delay or prevent the disorder in people who are at high risk. Because taking zinc may cause copper-deficiency anemia, the Institute recommends adding 2 mg of copper as cupric oxide to the daily regimen. A doctor should always be consulted before beginning this regimen of vitamin and mineral supplements.
