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.
By Dr. David F. Box, Ophthalmologist
Macular Degeneration is a common diagnosis for patients over age 50. The incidence increases in each subsequent decade of life. Patients who receive this diagnosis often become emotionally distraught because they believe it always results in blindness.
While it is true that some cases can lead to central loss of vision, that is not true the majority of the time. Although there is still much to be learned about this ocular disease, active research is making progress and the overall prognosis is improving.
New medications have been developed and risk factors are being identified. There are several promising new treatments on the horizon that should improve the prognosis even more. The information for this article was obtained from the National Eye Institute.
The disease causes damage to the macula, which is a small area located in the central portion of the retina. The macula contains a high density of the visual nerves needed for sharp central vision. Patients with damage in the macular region of the eye will notice blurring and distortion of central vision. Sometimes this damage can be spotty and not all areas of the macula are equally involved.
In more severe cases, all of the macular cells are damaged and the patient will completely lose central vision in the affected eye. A person with loss of macular function would still have peripheral visual input but would lose ability to read, drive and recognize faces. Most of the cases involve both eyes, but the degree of severity between the two can vary significantly.
Another variable among patients is the rate of progression. The disease does not spontaneously improve and usually worsens gradually. Some patients have much faster progression than others. The rate of progression can also differ between eyes in the same patient.
There have been risk factors identified in macular degeneration patients. In general, age seems to be the most important risk factor. Often you will see the disease identified by the acronym AMD, which is an abbreviation for Age-Related Macular Degeneration.
Researchers are trying to learn more about the specific age changes occurring in the retinas of affected patients. Smoking has been shown to double the risk of AMD. People with a family history of AMD are also at a higher risk. AMD is more common among Caucasians than among African-Americans or Hispanics/Latinos.
Researchers have found links between AMD and some lifestyle choices. Patients may be able to reduce their risk of AMD or slow its progression by making these choices: avoid smoking, exercise regularly, maintain normal blood pressure and cholesterol levels, eat a healthy diet rich in green leafy vegetables and fish.
AMD can only be detected by a comprehensive dilated eye exam performed by an eye care professional. As in many medical conditions, an accurate and early diagnosis of AMD is important in developing a proper treatment plan and providing appropriate counseling to the patient tailored to their specific findings.
Unfortunately, AMD shares symptoms with many other eye conditions. Misdiagnoses can occur. A delay in the proper diagnosis could have a significant impact on the course of the disease. If a patient receives an improper diagnosis of AMD, then this can lead to avoidable anguish and fear for the patient and their family.
It is very important to make the proper diagnosis as early as possible in the course of AMD. Proper grading and staging of the severity of the disease in each eye is valuable for many reasons. In order to accomplish this objective, eye care professionals must possess proper training and experience in managing AMD. They must also have access to additional diagnostic tests and equipment.
At the Indiana Eye Clinic, all of our eye physicians are well-trained in the diagnosis and management of AMD. We also have the most advanced equipment currently available onsite to assist us in caring for our AMD patients.
In subsequent articles, I will discuss some more specific details about various types of AMD and current treatment options available.