Macular degeneration

Macular degeneration is the leading cause of vision loss among people age 50 and older. It is also called age-related macular degeneration.

Macular degeneration damages the macula, which provides sharp, central vision. The macula is the most sensitive part of the retina. It is located at the back of the eye. The retina turns light into electrical signals and then sends them through the optic nerve to the brain, where they are translated into the images we see. 

When the macula is damaged, the center of vision may appear blurry, distorted, or dark. Damage caused by macular degeneration can interfere with:

• the ability to see straight ahead. This is necessary when recognizing faces, watching television, or driving.
• fine, detailed vision. This is necessary for reading newsprint, sewing, working with crafts and making repairs.

There are two forms of macular degeneration:

Dry macular degeneration. Most people with macular degeneration have this type. The cells of the macula slowly break down. This produces blurring at first, then blank spots in the eye's central vision. In the beginning, the symptoms are subtle, then become more noticeable. Some cases of dry macular degeneration progress to the more serious wet macular degeneration.

Wet macular degeneration. Everyone with wet macular degeneration starts out with the dry form. At some point, new blood vessels begin to grow beneath the retina. The new vessels leak blood and fluid into the macula, causing scarring. Wet macular degeneration can cause rapid loss of vision over days to weeks and continued loss of vision over time.

Symptoms of macular degeneration

Dry macular degeneration sometimes doesn't cause any symptoms. When symptoms do occur, they may include:

• increasingly blurred vision
• faded colors
• difficulty recognizing faces
• gradual increase in the haziness of central vision
• straight lines appear wavy or crooked
• blurred or blind spot in the center of your field of vision

Symptoms of wet macular degeneration begin abruptly and worsen rapidly. They include:

• distorted vision; straight lines may appear wavy or crooked
• decreased central vision
• decreased intensity or brightness of colors
• blurry or blind spot in your field of vision

Macular degeneration generally does not affect side vision, even in advanced cases.

Diagnosing macular degeneration

Regular eye exams can detect macular degeneration before sight is affected and before permanent visual loss occurs. A complete eye exam should include the following components.

• visual acuity test. This test measures how well you see at different distances (with glasses, if needed).
• dilated eye exam. In a dilated eye exam, drops put in the eye expand (dilate) the iris and allow a clear view deep inside the eye. The doctor will be looking for yellowish spots under the retina, called drusen, and other abnormal changes that may indicate macular degeneration.

If you have risk factors for macular degeneration, or if your doctor suspects that you have the condition, he or she might recommend the following tests:

Amsler grid test. This test can help identify the distorted vision typical of macular degeneration. It uses a drawing of vertical and horizontal lines with a dot in the middle. You are asked to stare at the dot. If you have macular degeneration, some of the lines will appear bent or distorted. As the condition gets worse, you may notice a black or dark space at the center of your visual field.

Fluorescein angiography. In this test, a special dye is injected into your arm. As the dye travels through the blood vessels in the retina, your doctor takes multiple photographs with a special camera. The images reveal whether the blood vessels in your eyes are leaking and where any abnormalities are located.

Treating macular degeneration

There is no cure for wet or dry macular degeneration. But treatments can help slow or stop the disease from getting worse. The earlier treatment is started, the more vision is likely to be saved.

Dry macular degeneration

Research from the National Eye Institute has found that a combination of supplements can slow (and sometimes even prevent) dry macular degeneration from getting worse. It includes:

• vitamin C: 500 milligrams (mg)
• vitamin E: 400 international units (IU)
• beta carotene: 15 mg
• zinc: 80 mg
• copper (cupric oxide): 2 mg

Talk with your doctor before starting this kind of vitamin regimen.

Your doctor may also recommend a well-balanced diet that includes:

• leafy green vegetables like spinach, collard greens, and kale
• several servings of fish per week
• nuts

Smoking is a major risk factor for macular degeneration. If you smoke, ask your doctor about quit-smoking resources.

Dry macular degeneration worsens slowly. As a result, people usually manage quite well in their daily routines even with some loss of central vision.

Wet macular degeneration

Drugs known as anti-vascular endothelial growth factors (anti-VEGF) have revolutionized the treatment of wet macular degeneration.

Anti-VEGF therapy. When injected into the eye, these drugs stop the growth of new abnormal blood vessels. They also decrease leakage from those vessels. Anti-VEGF therapy may even restore lost vision.

Other treatments temporarily slow the worsening of wet macular degeneration, but they don't stop or reverse existing damage. They are used much less frequently than anti-VEGF therapy.

Laser surgery. Laser surgery burns the leaky blood vessels to seal them. But laser treatment can also destroy some surrounding healthy tissue, thereby harming vision.

Photodynamic therapy. A light-activated drug is injected into a vein in your arm. The drug moves through your body and to your eyes. The doctor shines a light into your eyes to activate the drug. The activated drug kills abnormal blood vessels.

Treatment of wet macular degeneration is changing quickly. Make sure to seek treatment from a retinal specialist who has kept up to date on this rapidly evolving field.

Living with low vision

If you have already lost some of your vision to macular degeneration, low-vision aids can help maximize the sight you have left. Optical devices include:

• magnifying spectacles
• handheld magnifying lenses
• stand magnifiers
• computer monitors with large type
• non-optical devices:
• books and newspapers with large print
• talking computers, watches, clocks, and calculators
• high-contrast watch dials
• enhanced lighting