A Guide to Macular Degeneration: The Leading Cause of Blindness
Dr. Joseph Myers, OD FAAO
Age-related macular degeneration (AMD) is a disease associated with aging that gradually reduces central vision, making reading and driving difficult. AMD affects the macula, the part of the eye that gives you 95% of your vision, including color vision. The macula is located in the center of the retina where we get our central and most important vision. With AMD, the disruption of the macular tissues inhibits a sharp image, resulting in a painless, gradual loss of vision.
Drusen are yellow deposits under the retina. Drusen alone do not cause vision loss, however, an increase in the size or number of drusen raises a person's risk of developing AMD causing vision loss. These deposits block nourishment to a healthy macula, causing poor function, distortion and potentially vision loss.
Dry Macular Degeneration occurs when the macula slowly breaks down, drusen and deposits occur, and blurring of central vision takes place. The most common symptom of dry AMD is slightly blurred vision, from difficulty recognizing faces, to needing more light for reading. Dry AMD generally affects both eyes, but vision can be worse in one eye. Dry AMD is more common, however, may turn into the wet form.
Wet Macular Degeneration occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels are very fragile and leaky. Blood and fluid may leak from the vessels, damaging the macula. Loss of central vision can occur quickly. A symptom of wet AMD is that straight lines appear wavy and blurred vision.
Risk for AMD:
- Smoking. Smoking increases the risk of AMD.
- Age. people over 60 are at greater risk than any other age groups
- Obesity. Research studies suggest a link between obesity and the progression of early and intermediate stage AMD to advanced AMD.
- Race. Whites are much more likely to lose vision from AMD than African Americans.
- Family history. Those with immediate family members who have AMD are at a higher risk of developing the disease.
- Gender. Women appear to be at greater risk than men.
Treatment- Dry: Treatment will only delay and possibly prevent AMD from progressing. The National Eye Institute's AREDS and AREDS 2 studies found that taking a specific high-dose formulation of antioxidants and zinc significantly reduces the risk of AMD and potential vision loss. The AREDS 2 formulation is not a cure for AMD. It will not restore vision already lost from the disease. However, it may delay the onset AMD, and help people who are at high risk for developing AMD. If you are already taking daily multivitamins, be sure to review all your vitamin supplements with your primary care doctor before you begin.
Treatment- Wet: The disease and loss of vision may progress despite treatment, and again is not a cure. The treatment is solely an attempt at preserving vision, and slow progression. Wet AMD can be treated by injections into the eye (anti-VEGF therapy). Abnormally high levels of a specific growth factor occur in eyes with wet AMD and promote growth of abnormal blood vessels. This drug treatment blocks the effects of the growth factor. You may need multiple injections that may be given as often as monthly. Laser surgery can also destroy the fragile, leaky blood vessels. Repeated treatments may be necessary.
Eat foods containing antioxidants and taking supplements. Foods with antioxidants are those rich in vitamins A, C and E. People, who eat diets rich in vegetables and leafy green vegetables, may have a lower risk of macular degeneration. Two of the 3 macular pigment components that are essential to macular function are lutein, zeaxanthin, and mesoxanthin. Higher dietary intake of these, is essential to decreasing the risk of ARMD and drusen.
1. Taking AREDS 2 formula: The Age-Related Eye Disease Study also indicates supplements of vitamin C, E are effective in reducing the risk of vision loss. However, beta-carotene has been linked to increased risk of lung cancer in smokers and was REMOVED in the new AREDS formulation. Do not take beta-carotene if you continue to smoke. Ask your doctor about these supplements before trying anything on your own.
AREDS 2 formula: 500 mg vit C, 400 IU vit E, 10 mg lutein, 2 mg Zeaxanthin, 350 mg DHA, 650 mg EPA, 25 mg zinc, 2mg copper
***** Types: Macuhealth, I-caps, preservision, ocuvite, pro-optics and others. ******
Vit C: fruits, peaches, peppers, strawberries, broccoli, brussel sprouts, orange /grapefruit/ grape juice
Vit E: tomato products, sunflower seeds/oil, almonds, spinach, cereals (total, raisin bran, special k)
Zinc: oysters, beans, beef, crab, turkey, lamb
Lutine/zeaxanthin: spinach, kale, beets, squash, peas, egg noodles, pumpkin, corn, broccoli, brussel sprouts
Omega 3: salmon, mackerel, sardines, cod liver oil, canned white tuna, almonds
2. Stop smoking. Smokers are higher risk for development of macular degeneration
3. Manage your other diseases. Take your medication and follow your doctor's instructions.
4. Get regular eye exams. Early detection of macular degeneration increases your chances of preventing serious vision loss. Normal eye health exams should be done yearly or more frequently if you have a family history of, or have macular degeneration.
5. Monitor your vision with an AMSLER GRID. You will cover one eye and stare at a black dot in the center of the grid. While staring at the dot, notice if the straight lines in the pattern appear wavy peripherally; notice if lines are missing. These may be signs of AMD