Age-related Macular Degeneration – What you need to know

by Dr. Jaclyn Kovach

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss among Americans age 50 and older and likely affects over 30,000 individuals in Naples. This condition causes damage to the macula, a small spot near the center of the retina, which is a tissue that lines the inside back portion of the eye similar to wallpaper.

The macula is composed of millions of light-sensing cells that provide sharp, central vision. It is the most sensitive part of the retina, which turns light into electrical signals that are sent through the optic nerve to the brain, where they are translated into the images we see.

As AMD progresses, a blurred area near the center of vision is a common symptom. Over time, the blurred area may grow larger and blank spots may develop in the central vision. AMD by itself does not lead to total blindness, however, the loss of central vision in AMD can interfere with simple everyday activities, such as the ability to drive, read, and write.

Age is a major risk factor for AMD. The disease is most likely to occur after age 55. Other risk factors for AMD include smoking, Caucasian race, positive family history for the condition, and even elevated blood pressure and cholesterol may play a role.

AMD is most often diagnosed prior to the development of visual symptoms, when a retina specialist performs a dilated eye exam and examines the person’s macula. This is why it is important for everyone over age 55 to have yearly, dilated eye examinations. In addition to checking visual acuity during the eye exam, the ophthalmologist will perform an Amsler grid evaluation. Changes in central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD. An optical coherence tomography test will also be performed during the visit. This quick and painless imaging modality projects light waves onto the macula, creating an image of your macula at a microscopic level. This is one of the most sensitive ways of diagnosing AMD in its earliest form.

During the eye exam, the retina specialist will look for drusen, which are yellow deposits under the macula. Most people develop some very small drusen as a normal part of aging. The presence of medium drusen indicates the first stage of AMD, known as early AMD. People with early AMD typically do not have vision loss. Another sign of AMD is the appearance of pigmentary changes under the retina. The development of these changes and the presence of large drusen are indicative of progression to intermediate AMD. Most people with intermediate AMD will not experience any symptoms.

People with late AMD suffer vision loss from two causes: damage to the light-sensing cells of the retina, called geographic atrophy and/or the
development of wet AMD. In wet AMD (also called neovascular AMD), abnormal blood vessels grow under the macula. These vessels leak fluid and blood, which leads to swelling and damage of the light-sensing cells in the macula. The damage may be rapid and severe, unlike the more gradual course of geographic atrophy. It is possible to have both geographic atrophy and neovascular AMD in the same eye, and either condition can appear first. It is also possible to have one eye with a later stage of AMD than the other.

Right now, there is no cure for AMD. Researchers have found links Age-related between AMD and some lifestyle choices. You might be
able to reduce your risk of AMD or slow its progression by avoiding smoking, exercising regularly, maintaining a normal blood pressure and cholesterol levels, and eating a healthy diet rich in green, leafy vegetables and fish.

Researchers at the National Eye Institute tested whether taking nutritional supplements could protect against AMD in the Age-Related Eye Disease Studies (AREDS and AREDS2). They found that daily intake of certain high-dose vitamins and minerals can slow the progression of the disease. People with a diagnosis of AMD should take the following clinically-proven vitamin supplementation regimen which is offered over-thecounter by several companies (Bausch & Lomb, Alcon).

• 500 mg of vitamin C
• 400 IU of vitamin E
• 80 mg zinc
• 2 mg copper
• 10 mg lutein
• 2 mg zeaxanthin

This vitamin regimen is currently the only FDA approved treatment for non-neovascular AMD.

Almost 10 years ago, treatment of wet AMD (neovascular AMD) by medications injected into the eye became standard of care. With neovascular AMD, abnormally high levels of vascular endothelial growth factor (VEGF) are secreted in the eyes. VEGF is a protein that promotes the growth of new abnormal blood vessels. Anti-VEGF injection therapy blocks this growth. Multiple monthly injections are usually required. Before each injection, the eye is numbed and cleaned with antiseptics. A few different anti-VEGF drugs are available, including bevacizumab (Avastin), ranibizumab (Lucentis), and aflibercept (Eylea). They vary in cost and in how often they need to be injected, so you may wish to discuss these issues with your retina specialist. It is important to remember that even though these therapies increase the chance of vision preservation, they are not a cure for wet AMD.

Age-related macular degeneration is a common and potentially devastating condition. The only way to decrease the risk of developing AMD is to lead a healthy lifestyle. The best way to maximize visual potential with the condition is to get regular eye exams and treatment, as needed, and to visit your retina specialist if you notice any sudden changes in your vision or on your Amsler grid.