The retina is the delicate innermost layer of tissue that lines the back of the eye; the macula is the central portion of the retina, and helps us perceive fine visual detail. Age-related Macular Degeneration (AMD) causes degeneration of light sensitive cells of the macula, resulting in a loss of central vision.
Early onset forms of macular degeneration strike children and young adults, but AMD is the leading cause of legal blindness in people over the age of 55; about six million Americans and one-third of people over 75 have AMD. This is slated to increase as the population continues to grow older.
Although the exact causes of AMD are not well understood, researchers have found evidence that both inherited and environmental factors influence the risk of developing this disease. It seems to run in families, and researchers are working to have a better understanding of which genes are involved. This may help to develop treatments and cures. Additionally, genetic research may eventually allow doctors to identify and treat patients at risk of developing the disease before their vision is lost.
Environmental risk factors are age, cigarette smoking, early menopause, high blood pressure, cardiovascular disease, prolonged sun exposure and diets high
In certain fats. A generally healthy diet low in saturated fats and high in fruits and vegetables appears to be associated with a decreased risk of AMD.
The two types of AMD are “dry” and “wet.” Ninety percent of all cases are the dry type and most of these cases progress very slowly over a period of years, although some patients with dry AMD have an increased risk of developing the wet type. Wet AMD usually leads to a rapid loss of central vision.
AMD does not lead to total blindness, as most of these patients retain peripheral vision and can learn to optimize the use of their remaining vision; however, many of these people are classified as legally blind.
In 2001, the Age-Related Eye Disease Study (AREDS) sponsored by the National Eye Institute, a division of the National Institutes of Health, reported the results of a study that concluded the effects of some antioxidants plus minerals on AMD patients. It was found that these substances can reduce the risk of, as well as reduce vision loss in advanced AMD. The supplements do not help patients with minimal AMD, or prevent the initial development of AMD, or improve vision already lost. The antioxidant supplements used in the study were daily doses of Vitamins C, E, Beta Carotene, and the minerals zinc and copper.
Very few side effects from the supplements were found, but smokers and ex-smokers were advised not to take beta-carotene, as it was shown in previous large clinical trials sponsored by the National Cancer Institute to significantly increase the risk of lung cancer in these people. It was also recommended to take a small amount of copper (as cupric oxide) because high dose zinc may be associated with copper deficiency, affecting the immune system.
That study did not investigate whether the antioxidant lutein was of any benefit, but abundant scientific information since then indicates that lutein does help reduce the risk of AMD.
In 2013, the formula was changed. Named AREDS-2, the new formulation replaced beta-carotene with lutein and zeaxanthin (in the same class as beta-carotene), and the dose of zinc was lowered.
Even normal-sighted people who take lutein supplements report reduced glare, a brighter view and sharper vision. This could be especially helpful for anyone exposed to brilliant sunlight or an excess of television or computer screens on a daily basis, particularly those with blue eyes. Taking supplemental lutein after a meal containing a little fat helps absorption.
To prevent losing vision to AMD, have regular eye exams, which will allow early detection and diagnosis, as treatments are available. Although these treatments cannot restore lost vision, they can slow the progress of the disease and delay severe vision loss for some patients. It is especially important to see a doctor if you notice changes in your central vision.
The Foundation Fighting Blindness is the world’s largest non-governmental source of funding for degenerative retinal diseases, including macular degeneration. They are continually working on the causes, treatment, preventions and cures for these diseases.