Age-related macular degeneration (AMD) is a disease of the eye that causes progressive loss of detailed, central vision. According to the Duke Center for Human Genetics, AMD is a complex disease that is thought to be caused by the interaction of multiple environmental, lifestyle and genetic factors.
Age
According to the National Eye Institute, the greatest risk factor for developing AMD is age. While those who are middle-aged carry approximately a 2 percent risk of getting the disease, the risk increases to 30 percent in those older than 75. Though in some cases, the onset of AMD may be abrupt, AMD usually progresses slowly over a period of years, causing increasing loss of visual sharpness as we age.
Genetic and Demographic Causes
Age-related macular degeneration is a condition that may in some cases be caused by inherited abnormalities in certain genes. According to the Duke Center for Human Genetics, multiple variants of a gene called compliment factor H (CFH) have previously been found to account for up to 43 percent of AMD cases. Ongoing research is being conducted to clarify other genes that play a role in causing--or protecting us from developing--AMD.
Other demographic factors such as gender and race can influence our risk for developing AMD. According to the National Eye Institute, women are at higher risk of getting AMD than men. Caucasians also are much more likely than African-Americans to develop the disease.
Nutrition
According to the American Macular Degeneration Foundation, deficiencies in certain nutrients can affect the health of the macula. The foundation says that consuming fruits and leafy green vegetables that contain two carotenoid pigments called lutein and zeaxanthin may help to protect against developing AMD. The foundation also note thes importance of additional vitamins in preventing the worsening of AMD after its onset, citing evidence from the Age-Related Eye Disease Study (AREDS) published in the October 2001 issue of the "Archives of Ophthalmology." The study found that individuals at risk of developing advanced AMD decreased their risk by 25 percent when given high doses of vitamin C, vitamin E, beta-carotene and zinc.
Other lifestyle choices such as diet and exercise can influence your blood pressure and cholesterol levels, both of which have profound effects on eye health. Obesity, diabetes, hypertension and high cholesterol can all increase intraocular pressure and reduce blood flow to the eye, increasing your risk for developing AMD or other eye diseases.
Smoking
The American Macular Degeneration Foundation states that smokers are four times more likely than non-smokers to develop AMD. The toxic compounds in cigarettes may interfere with the delivery of protective nutrients to the eye. Smoking may also reduce blood flow and oxygen to the eye, potentially damaging the retina and macula.
