Monthly Archives: May 2016
By David F. Box, M.D.
In a previous article I discussed Age-related Macular Degeneration (AMD) in which we discussed the signs and symptoms of this disease, as well as the various forms of AMD. Now let’s talk about the various treatment options currently available for AMD.
The information for this article was primarily obtained from the American Academy of Ophthalmology website. (www.aao.org, Treatment of Macular Degeneration, Boyd and Janigian, MD). Please refer to this website for additional information.
To briefly review, macular degeneration is usually classified into two major categories. Wet macular degeneration involves leakage of fluids and blood into the central portion of the retina. The leakage causes vision nerves to fail and scar tissue to develop in the macula of the eye.
The macula of the eye is the location of the highest density of vision nerves. Damage in this area causes decreased central vision and distortion of vision. In severe cases, patients may lose their ability to read clearly, recognize faces or drive a car. Patients will still retain peripheral vision that can be useful for some visual tasks requiring less visual acuity.
Dry macular degeneration involves a gradual failure in the macular nerves as well, but there is no bleeding or leakage of vessels. Usually the scar tissue damage occurs at a slower rate in dry macular degeneration than in wet macular degeneration. However, the visual damage can be equally severe in both forms of the disease.
The exact causes of these diseases is unknown, but research has identified certain risk factors that may contribute to AMD. Yearly eye exams for patients over 60 years old performed by a trained Ophthalmologist may also help to identify patients who are more at risk for AMD. All of our doctors at the Indiana Eye Clinic are thoroughly trained in the diagnosis and management of macular degeneration.
Even though both forms of AMD can cause decreased central vision, research has shown that they are not the same disease. They must be treated differently, even though they are closely related.
It is not unusual to see a patient with dry AMD develop wet AMD in one or both eyes. Sometimes patients with wet AMD will change to the dry form of the disease, although this is a much less likely occurrence.
Research has shown that there are some treatments that seem to help both forms of the disease, whereas other treatments must be individualized to the specific type of AMD. To date, treatments for the dry form of macular degeneration have been more elusive to discover.
Treatment options for the wet form of macular degeneration are more plentiful, but considerable research still remains to be done to obtain better results. Even though there are fewer treatment options available for dry AMD, it is still generally considered to be a milder form of the disease.
Dry macular degeneration usually progresses at a much slower rate. In many patients the visual decrease may not be as severe as can be seen in wet macular degeneration. In wet macular degeneration, the leakage of fluid from abnormal blood vessels in the macula can cause a much more rapid decrease in vision and formation of permanent scar tissue.
The Age-Related Eye Disease Study 2 (AREDS2) showed that people at high risk for developing wet macular degeneration who took a dietary supplement of 500 mg vitamin C, 400 IU vitamin E, 10 mg Lutein, 2mg Zeaxanthin, 80 mg Zinc and 2mg Copper lowered their risk of progression to advanced stages of wet macular degeneration by at least 25 percent.
The supplements did not appear to provide a benefit for people with minimal macular degeneration or people without evidence of the disease during the course of the study. These vitamins are recommended in specific daily amounts in addition to a healthy balanced diet.
Other studies have shown that eating dark leafy greens, and yellow, orange and other colorful fruits and vegetables rich in lutein and zeaxanthin, may reduce your risk of developing macular degeneration.
Several studies show that smoking increases the risk of developing macular degeneration, so smoking cessation is highly recommended.
It is important to remember that vitamin supplements are not a cure for macular degeneration. They will not give you back vision that you may have already lost from the disease. These supplements do play a key role in helping some patients at high risk for developing advanced (wet) macular degeneration to maintain their vision or slow down the progression of the disease.
A common way to treat wet macular degeneration targets a chemical in your body that causes abnormal blood vessels to grow under the retina. The chemical is called vascular endothelial growth factor, or VEGF. Several new anti-VEGF drugs have been developed for wet AMD. Blocking VEGF reduces the growth of abnormal blood vessels, slows their leakage, helps to slow vision loss and in some cases improves vision.
Your ophthalmologist administers the anti-VEGF drug (such as Avastin, Eylea, or Lucentis) directly into your eye after applying anesthetic drops in an outpatient procedure. A patient may receive multiple anti-VEGF injections over the course of many months. Repeat anti-VEGF treatments are often needed for continued benefit.
It is important to remember that only about 10 percent of all macular degeneration cases are of the wet form. Dry AMD is much more common. At the present time only 25 percent of the wet macular degeneration cases can be successfully treated. Considerable research is currently underway to try to improve these statistics.
Patients who have untreatable forms of macular degeneration will not become blind. They will still retain their peripheral or side vision. Patients with low-vision may be helped by visual rehabilitation, devices and services. People with low-vision can often learn new strategies and techniques to help them accomplish daily activities and live independently despite loss of central vision.