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 dry form of AMD causes a slow breakdown of light-sensitive cells in the retina. In most cases, this does not greatly affect the vision. The dry form of AMD is much more common than the wet form. The wet form occurs when a patient with the dry form grows abnormal blood vessels under the retina. These vessels leak blood and fluid and cause scarring. Vision loss from this damage can happen quickly.

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. Vision loss from AMD is more common in 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 geographic 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 care provider 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 injected into a vein in your arm. The dye travels through the blood vessels in your retina and can be seen with photographs. 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.

Medicines that shrink the blood vessels are available. Lucentis is a drug that causes shrinkage of the abnormal blood vessels when it is injected into the eye. The shots need to be repeated every 1 to 3 months. Lucentis can maintain vision in most patients (95%) and improve vision in many patients (25-40%). Lucentis is generally the first choice for treatment of wet AMD.

Macugen is a drug that needs to be injected into the eye every 6 weeks. It can help decrease vision loss. It may be used in types of wet AMD where laser treatments are not possible. Other medicines may soon be available.

Sometimes injections are not effective or do not last long enough. In these cases laser treatment can be done, if the abnormal blood vessels under the retina are not under the very center of the macula. For this treatment, a laser is used to seal the blood vessels. This helps decrease the chance of further vision loss.

If your blood vessels are growing under the center or very close to the center of your macula, your eye care provider 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 three or more months later. It may help stop or slow down more vision loss, but it does not improve vision in most cases.

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 provider 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 care provider has determined that you have a high risk for AMD.

Zinc and high doses of beta carotene have possible health risks. Ask your provider 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.