Macular Degeneration (ARMD)
At the Beaumont Eye Institute we know that Age-Related Macular Degeneration (ARMD) is the leading cause of vision loss in people over 50 in the United States. That's why our Board Certified doctors are highly trained in treating this disorder. In fact the Beaumont Eye Institute is the only eye center in Michigan exploring a new surgery for ARMD. Over 13 million people already suffer from this type of blindness and a quarter million new patients are diagnosed each year. A Beaumont ophthalmologist will assess your risk factor for ARMD, and if necessary, begin treatment that's right for you.
Age-related macular degeneration (ARMD) is a disease that affects an individual's central vision. ARMD is the most common cause of severe vision loss among people over 60. Because only the center of vision is affected, people rarely go blind from this disease. However, ARMD can make it difficult of read, drive, or perform other daily activities that require fine, central vision.
ARMD occurs when the macula, which is located in the center of the retina and provides us with sight in the center of our field of vision, begins to degenerate. With less of the macula working, central vision - which is necessary for driving, reading, recognizing faces, and performing close-up work - begins to deteriorate.
Types of ARMD
There are two primary types of ARMD:
- Dry ARMD - This type of ARMD is responsible for 90 percent of disease cases. While its cause is unknown, it occurs as the light sensitive cells in the macula slowly deteriorate, generally occurring in one eye at a time.
- Wet ARMD - This type of ARMD is responsible for 10 percent of disease cases, but accounts for 90 percent of all severe vision loss caused by either type of ARMD. Wet ARMD occurs when new blood vessels behind the retina start to grow beneath the retina where they leak fluid and blood and can create a large blind spot in the center of the visual field. If this happens, there is a marked disturbance of vision in a short period of time.
Symptoms of ARMD
The following are the most common symptoms of ARMD. However, each individual may experience symptoms differently. Symptoms may include:
- Blurry or fuzzy vision
- Difficulty recognizing familiar faces
- Straight lines, such as sentences on a page, telephone poles, and the sides of buildings, appear wavy a dark or empty area (blind spot) appears in the center of vision
- Rapid loss of central vision - vision necessary for driving, reading, recognizing faces, and performing close-up work
The presence of drusen, tiny yellow deposits in the retina, is one of the most common early signs of ARMD. These will be visible to your physician during an eye examination. While the presence of drusen alone does not indicate the disease, it may mean the eye is at risk for developing more severe ARMD.
The symptoms of ARMD may resemble other eye conditions. Consult a physician for diagnosis.
In addition to a complete medical history and eye examination, your ophthalmologist may perform the following tests to diagnose ARMD:
- Visual acuity test - the common eye chart test (see right), which measures vision ability at various distances.
- Pupil dilation - the pupil is widened with eye drops to allow a close-up examination of the eye's retina.
- Amsler grid - used to detect wet ARMD, this diagnostic test uses a checkerboard-like grid (reduced size shown here; normal vision on the left and vision with ARMD on the right) to determine if the straight lines in the pattern appear wavy or missing to the patient - both indications may signal the possibility of ARMD.
- Fluorescein angiography - used to detect wet ARMD, this diagnostic test involves a special dye injected into a vein in the arm. Pictures are then taken as the dye passes through the blood vessels in the retina, helping the physician evaluate if the blood vessels are leaking and whether or not the leaking can be treated.
- Ocular coherence tomography - a test to measure the thickness of the retina.
Risk Factors for ARMD
A risk factor is anything that may increase a person's chance of developing a disease. It may be an activity, such as smoking, diet, family history, or many other things. Different diseases, including cancers, have different risk factors.
Although these factors can increase a person's risk, they do not necessarily cause the disease. Some people with one or more risk factors never develop the disease, while others develop disease and have no known risk factors.
But, knowing your risk factors to any disease can help to guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.
Possible risk factors for ARMD include:
According to some studies, women are at greater risk than men.
Although ARMD can occur during middle age, the risk for developing the disease increases as a person ages. Studies have shown that while persons in their 50s have only a two percent risk of developing ARMD, that rises to nearly 30 percent in persons over 75.
Recent studies have shown that smoking is a major risk factor for age-related macular degeneration.
- Family history
Persons with a family history of ARMD may have a higher risk of developing ARMD.
- High blood cholesterol levels
Persons with elevated blood cholesterol levels may be at higher risk for wet ARMD.
Treatment for ARMD
Specific treatment for ARMD will be determined by your physician based on:
- Your age, overall health, and medical history
- Extent of the disease
- Your tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
Treatment for wet ARMD may include laser surgery in which a high energy beam of light is aimed directly onto the leaking blood vessels to deter further leaking; photodynamic theraphy which uses a drug and laser in combination; and new drugs called angiogenesis inhibitors are also used.
Currently, there is no treatment for dry ARMD. This does not, however, indicate that sight will automatically be lost, particularly if the ARMD affects only one eye. Central vision may eventually be lost or diminished, but generally the rate of loss is slow.
Zinc and Antioxidants Reduce Risk of Advanced ARMD
Beaumont Hospital was the only hospital in Michigan to participate in a 2002 study which found that people with ARMD who take a simple regimen of antioxidants and high levels of zinc significantly reduce their risk of advanced ARMD. All of the participants in the study had varying stages of ARMD. In the study, those participants taking a combination of antioxidants and zinc reduced their risk of developing advanced ARMD by 25 percent and their risk of vision loss by 19 percent.
Even taking antioxidants alone reduced the participants' risk of developing advanced ARMD by 17 percent and the risk of vision loss by 10 percent. Taking zinc alone reduced the participants' risk of developing advanced ARMD by 21 percent and their risk of vision loss by 11 percent.
Although these supplements are readily available over the counter, the researchers recommend that anyone considering taking them should consult his/her ophthalmologist. The supplements may cause side effects and/or interact with other prescription and over-the-counter medications.