Age-Related Macular Degeneration Overview

What Is Age-Related Macular Degeneration?

Age-related macular degeneration is the leading cause of severe vision loss in people over age 60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye.

Although it almost never causes complete blindness, age-related macular degeneration can be a source of significant vision loss.

The macula is the most important region of the eye. It is a very small portion of the retina and is about the size of a pencil eraser. The macula is loaded with photoreceptors that allow you to read, watch television, drive, sew -- anything that requires focused, precise vision.

Outside of the macula there are far fewer photoreceptors and image resolution is much poorer. Although these uninvolved portions of the retina can continue to process images along the edge your field of vision, the tissue damage caused by macular degeneration distorts or obscures part of the crisp central images that your eye transmits to your brain.

In the dry form of macular degeneration, tiny yellow deposits develop beneath the macula, signaling a degeneration and thinning of nerve tissue. A small number of cases develop into the wet, or neovascular, form of macular degeneration, in which abnormal blood vessels grow beneath the macula. As these vessels leak blood and fluid onto and underneath the retina, retinal cells die, causing blurs and blank spots in your field of vision.

Most patients with age-related macular degeneration have the dry form of the disease and will not lose central vision. However, the dry form of macular degeneration can lead to the wet form. Although only about 10% of people with macular degeneration develop the wet form, they make up the majority of those who experience serious vision loss from the disease.

It is very important for people with macular degeneration to monitor their eyesight carefully and see their eye doctor on a regular basis.

Age-Related Macular Degeneration Causes

No one knows the causes of age-related macular degeneration. Causes are likely to be genetically inherited, but environmental factors also contribute. Macular degeneration often runs in families. A recent study of twins showed that genetic factors play a significant role in the cause.

Many of the following risk factors have been found to be associated with age-related macular degeneration:

• Age: The likelihood to develop macular degeneration increases with age.
• Race: Macular degeneration is more common in whites but occurs in all races.
• Smoking
• High blood pressure
• Vascular disease
• High intake of saturated fat and cholesterol
• High blood cholesterol level
• Farsightedness (hyperopia)
• Exposure to sunlight
• Family history

What Are the Risk Factors for Age-Related Macular Degeneration?

As the name suggests, age-related macular degeneration is more common in older adults. In fact, it is the leading cause of severe vision loss in adults over age 60.

Macular degeneration may be hereditary, meaning it can be passed on from parents to children. If someone in your family has or had the condition, you may be at higher risk for developing macular degeneration. Talk to your eye doctor about your individual risk.

Smoking is also significant risk factor for macular degeneration.

Questions to Ask the Doctor

• What can I do to decrease my chances of losing more vision?
• What low-vision aids are available to help me with my remaining vision?
• What symptoms should I watch for?
• What lifestyle changes should I make?
• What treatment options are available for my condition?