Slow the progress of a vision-robbing disease
If you are over 50, your age is a major risk for developing age-related macular degeneration (AMD), a painless disease that’s a leading cause of vision loss in older adults. Smoking doubles that risk, and other factors related to the disease include a family history, obesity, white race, and being a woman.
In AMD, the cells in your macula—a small area of the retina that contains light-sensing cells—begin to break down, causing straight-ahead images to appear dim, dark, blurry, or distorted.
Stages and types
“AMD can progress through three stages,” says David Rubaltelli, M.D., M.B.A., faculty attending at the Department of Ophthalmology and Visual Sciences, Montefiore Health System in Bronx, N.Y. “In the early stage, you are unlikely to notice any symptoms, and in the intermediate phase, you may or may not have minor changes in vision.”
These changes are due to the presence of drusen—yellow substances that are a byproduct of cellular activity of the retina.
When AMD becomes advanced, it can become the dry type or the wet type. “Dry AMD can also be referred to as geographic atrophy,” Rubaltelli says. “Drusen increases, and pigment cells are lost as the macula breaks down.”
The other type of advanced AMD, wet AMD, happens for a slightly different reason. “Abnormal blood vessels break through the layers of the macula, causing bleeding and swelling under the retina,” Rubaltelli explains. “Wet AMD tends to progress more rapidly, and significantly affects vision.”
Treatments can slow vision loss
Treatments for wet AMD include injections, photodynamic therapy, and laser surgery. These treatments are aimed at retarding the growth of the abnormal blood vessels. It is not a cure, however, and most people need multiple ongoing treatments. “The process can be likened to trying to eliminate weeds,” Rubaltelli says. “Like weeds, the blood vessels are very tenacious and treatments tend to slow the growth but need to be continued to keep them under control.”
No similar treatments currently exist for dry AMD. The National Eye Institute’s Age-Related Eye Disease Study found that taking certain supplements may slow progression of dry AMD to wet by about 25% in people with intermediate and late dry AMD. So far, there is no evidence that supplements are beneficial in early stages.
The supplements are called AREDS or AREDS2, and the basic nutrients include vitamin C, vitamin E, zinc oxide, and copper. ““Evaluation of the formula over the years has shown that adding omega-3 fatty acids was not statistically beneficial,” Rubaltelli says, “but adding two antioxidants called lutein and zeaxanthin may further reduce the risk of developing wet AMD.”
Some concern has emerged about beta-carotene, which used to be a standard part of all AREDS supplements. “Some scientific evidence suggested that beta-carotene supplements were linked to an increase in lung cancer among smokers, even among former smokers,” Rubaltelli says. “Beta carotene obtained through foods is safe, however.”
Although AREDS and AREDS2 are available over the counter, experts do not recommend that you start taking either of them without consulting your doctor. “Determining the best formula for you depends on your risk, medical history, family history, and type and stage of the disease,” Rubaltelli says.
What to do about low vision
AMD rarely causes total blindness, but low-vision specialists can help you deal with your level of visual impairment. Talk to your eye care professional about how to access services. “Low-vision specialists can help you see your best, and also help you find and tailor devices to fit your specific needs,” says Christine M. Kim, O.D., director of optometry for the Department of Ophthalmology and Visual Sciences at Montefiore Medical Center in Bronx, N.Y.
Technology can make life much easier. There are talking watches, calculators, clocks, and glucose monitors for people with diabetes. “Computer devices and programs can help individuals with low vision. Most smartphones and tablets now have built-in functions that can make the computer, phone, or tablet into a low-vision device,” Kim says. “For example, font size can be made larger, and there are voice-override functions that can read text on the screen for you. In addition, voice commands can help you find information without having to rely on your vision.”
Your doctor may recommend a vision rehabilitation program. These programs involve a team of professionals to help you train on adaptive devices, learn how to take care of daily living challenges, and modify your home if necessary.
Along with other risks, researchers believe that there are genes associated with the development of AMD. “While genetic studies show some promise, there is no evidence that commercially available genetic tests are predictive of AMD at this time,” Rubaltelli explains. “AMD, like many diseases, develops as a result of complex interactions among environmental factors and genetic makeup.” The American Academy of Ophthalmology does not recommend that people take commercial genetic tests for AMD at this time.
Research on AMD is aimed at better prevention, detection, and treatment to reduce vision loss. Some areas being studied are transplanting healthy cells into the retina, anti-inflammatory treatments for wet AMD, and learning more about hereditary factors.
There is nothing magical about preventive strategies for AMD; they are the same things everyone should do to avoid many chronic diseases. “With the aging of the U.S. population, AMD stands to become a major public health issue,” Rubaltelli says. “Protect yourself by avoiding smoking; getting regular exercise; eating a very healthy diet; and controlling any other medical problems such as high blood pressure, high cholesterol, and diabetes.”