Macular degeneration is the progressive loss of the ability to see at the center field of vision. It is caused by the degeneration of the macula, a small, opaque spot in the center of the eyes. The macula is also referred to as "yellow spot." These tiny yellow areas near the center of the retina are the place where visual perception is most acute.

Macular degeneration causes the destruction of these photo-receptors and creates a lack of pigment in the eyes. Reduced pigmentation is believed to be a risk factor in the development of the disease.

The age-related condition can affect one or both eyes. It commonly affects people over the age of 55 and may cause them to see wavy or blurry lines in the center of the field of vision.

Macular degeneration is the main cause of blindness in the United States, affecting over 17 million people. Over 500,000 new cases are diagnosed each year. Macular degeneration is painless and may go undetected for years.

Risk factors for the disease include:

• Low dietary intake of certain nutrients
• Age
• Smoking
• Excessive exposure to bright sunlight
• Gender
• Race
• Family history
• Light colored eyes
• High blood pressure

There are two types of macular degeneration--"Dry," which represents approximately 90% of cases, and "wet," which represents the remaining cases. "Dry" macular degeneration is particularly difficult to to treat primarily because it is not treatable with surgery and can eventually develop into the "wet" type.

"Wet" macular degeneration refers to the overgrowth of small veins under the macula, which then leak fluid. Laser surgery can halt the condition; unfortunatley, such surgery creates a blind spot in the middle of the macula. Unfortunately, the benefits achieved with surgery are not permanent. Eventually, venal re-growth recurs and fluid leaks into the macula again.

Zeaxanthin is an antioxidant compound that occurs naturally in the body. It protects the sensitive cells of the eye from harmful blue-light waves in much the same way that sunglasses do. Studies have shown that portions of the macula with the highest concentration of zeaxanthin are the last to degenerate. Levels of zeaxanthin decline with age.

Age-related zeaxanthin loss is suspected as a factor in both types of macular degeneration.

Zeaxanthin and lutein are both carotenoids (yellow pigments) found in high concentrations in yellow fruits and vegetables, and in dark green leafy vegetables, like spinach, collard, and kale. Carotenoids are absorbed into the blood and deposited preferentially in the eye tissues, where they protect against free-radicals and absorb harmful blue-light rays. Zeaxanthin is produced by the conversion of lutein in the eye.

Individuals with the highest consumption of spinach had an almost 90% reduction in their risk of developing macular degeneration.

In addition to a high dietary consumption of carotenoids, dietary supplements are often recommended by doctors for the prevention of macular degeneration.