Macular degeneration

Macular degeneration is the leading cause of legal blindness in the USA. Macular degeneration is mostly an age-related condition. It is rare among the young, but the incidence is nearly 25% by age 85. A recent estimate is that 13 million Americans over 40 have signs of macular degeneration. This is much higher than a previous estimate of 3.2 +/- 0.5 million people between 55 and 85 years of age, with another 0.9 million of the over-85 age group.

Heredity, race and sex contribute to the risk of macular degeneration; whites are more susceptible than blacks, Hispanics and women are twice as prone as men to develop it.

Lifestyle issues are important risk factors for this disease. A main characteristic of the disease is damage to the macula through oxidation. Oxidation is encouraged smoking, diets deficient in fruits and vegetables, large consumption of alcohol, saturated fats and cholesterol. Exposure to bright sunlight may be a risk factor for early age-related maculopathy. A US study found that people who spend more than five hours daily outside in the summertime have an increased risk of developing early age-related retina damage that can lead to vision loss. The study also linked wearing hats and sunglasses with a slightly - but insignificantly - lower chance of developing age-related maculopathy.