Age-Related Macular Degeneration

What is age-related macular degeneration?

Age-related macular degeneration (AMD) is a disease that damages the macula in the eye. The macula is in the center of the retina. The retina is the back part of the eye. The macula is responsible for helping you see fine details. The loss of central vision caused by AMD can make it hard to read, drive, or recognize faces.

AMD is a common problem for many people as they get older. It usually affects both eyes, but one eye may be affected before the other.

How does it occur?

There are two forms of AMD: wet and dry. The wet form of AMD occurs when new, fragile blood vessels grow under the macula. These vessels leak blood and fluid and cause scarring. Vision loss from this damage can happen quickly. In the dry form, the light-sensitive cells in the macula gradually break down. In both cases, a blind spot forms in or near the center of vision. The dry form is more common and causes a much slower and often less severe loss of vision.

The cause of AMD is not known. Smoking may contribute to the problem. You may also be at greater risk if you are obese, have high blood pressure, or have family members with AMD. It is more common in women and people of European descent.

What are the symptoms?

AMD does not cause pain. Most people with AMD in an early to intermediate stage do not have any symptoms and have normal vision. Only people with advanced AMD, wet AMD, or a very severe form of dry AMD called geographical atrophy have symptoms. These symptoms may include:

• blurred vision
• wavy appearance of straight lines (for example, a telephone pole may appear to be bent)
• a dark patch in the middle of words as you read
• a worsening of color vision.

If just one eye is affected, you may not notice the loss of vision when you are using both eyes. Usually your side (peripheral) vision is not affected.

How is it diagnosed?

Your eye doctor can diagnose this disease with an exam of the retina through dilated pupils. You may have a test called fluorescein angiography. In this test a dye is put into a vein in your arm. The dye travels to blood vessels in your retina and can be seen on X-ray pictures. The pictures can show where the leaking blood vessels are and help determine the best treatment.

How is it treated?

AMD in its early stage does not need treatment. If you are at high risk for AMD, your healthcare provider may suggest nutritional supplements that may help decrease your chance of vision loss.

There is currently no treatment to reverse vision loss from dry AMD, but a particular combination of vitamins and minerals can slow the progression of dry AMD in some cases.

There are several treatment options for wet AMD. If the abnormal blood vessels under the retina are not under the very center of the macula, laser treatment can be done. For this treatment, a laser is used to seal the blood vessels. This helps decrease the chance of vision loss.

If your blood vessels are growing under the center or very close to the center of your macula, your eye doctor may recommend a cold laser treatment (photodynamic therapy, or PDT). This treatment must be used instead of the "hot laser" to try to protect the surrounding normal tissue in the macula. For cold laser treatment, a light-activated dye is injected into your bloodstream. When the dye reaches the retina, a "cold" laser is used to activate the dye to close the leaking blood vessels. This procedure may need to be repeated. It may help stop or slow down more vision loss, but it does not improve vision in most cases.

Medicines that shrink the blood vessels are becoming available. Macugen is a drug that needs to be injected into the eye every 6 weeks for 2 years. It may help decrease vision loss. It may be used in types of wet AMD where laser treatments are not possible. Lucentis is another type of drug that causes shrinkage of the abnormal blood vessels when it is injected into the eye. Like Macugen, the shots need to be repeated at regular intervals. Other medicines may soon be available.

If you have advanced AMD, low vision aids may help you with your daily activities. Low vision aids include:

• magnifying glasses and telescopes
• closed-circuit TV
• clocks and phones with large numbers and reading material printed in large type.

Ask your healthcare provider for help in finding vision aids that will help you.

How can I take care of myself?

• Tell your doctor if your vision changes in any way.
• Never ignore blurred vision, straight lines that appear wavy, blind spots, or loss of color vision.

How can I help prevent AMD?

A healthy lifestyle may improve the chances of keeping good vision. This includes:

• not smoking
• eating a healthy diet
• good control of blood pressure and cholesterol.

A vitamin and mineral supplement containing beta carotene (vitamin A), vitamins C and E, zinc, and copper may help you decrease your chance of vision loss if:

• You have an advanced form of AMD in at least 1 eye, or
• Your eye doctor has determined that you have a high risk for AMD.

Zinc and high doses of beta carotene have possible health risks. Ask your doctor if this vitamin and mineral supplement is a good idea for you before you start taking it. Smokers may need to take different supplements than nonsmokers.