Macular degeneration is an eye disorder that makes it difficult to see fine details. The condition affects the macula, the part of the retina responsible for central vision.

Age-related macular degeneration (AMD), AMD, Senile macular degeneration (SMD)

Damage to the macula can gradually destroy central vision, which is used to read and see objects clearly.

Two types of macular degeneration (AMD) exist:

• Dry macular degeneration occurs when the macula becomes thin and dries out. Small yellow deposits, called drusen, form under the macula. As these drusen increase in size and number, they create a blurred spot in the central vision of the eye. Almost all people with macular degeneration have the dry form.
• Wet macular degeneration occurs when abnormal blood vessels grow under the macula and retina (this is called choroidal neovascularization). These vessels can leak blood and fluid, damaging the macula. Vision loss in the central vision can occur very quickly. Only about 10 percent of people with macular degeneration have this form, but it causes most of the vision loss associated with the condition.

Scientists aren't sure what causes AMD. The disease is most common in people over 60, which is why it is often referred to as age-related macular degeneration.

Other risk factors are:

• Caucasian race
• Cigarette smoking
• Family history
• Female gender
• Obesity

If you are over age 60 and you've had changes in vision, your eye care provider will do an examination. During the exam, the doctor will use drops to enlarge (dilate) your pupils, and a special magnifying lens to view your retina and optic nerve. The doctor will look for the yellow deposits called drusen that form in dry macular degeneration.

You may be asked to cover one eye and look at a pattern of lines called an Amsler grid. If the straight lines appear wavy, it may be a sign of AMD.

Other tests for macular degeneration may include:

• Fluorescein angiogram
• Tonometry
• Visual acuity test