Age-Related Macular Degeneration (AMD) is the most common cause of severe vision loss in older Americans. Macular degeneration is damage or breakdown of the macula of the eye. The macula is the central part of the retina responsible for high-resolution vision and is critical in tasks such as reading, driving, and other activities requiring fine visual discrimination. It allows us to see fine details clearly.
When the macula doesn't function correctly, we experience blurriness or darkness in the center of our vision. Macular degeneration affects both distance and close vision and can make some activities - like threading a needle or reading - difficult or impossible. Early symptoms include blurred vision or distorted vision. Objects may appear warped, or straight lines may appear wavy. Your ophthalmologist can often detect signs of macular degeneration before any loss of vision occurs. Because the early form of macular degeneration does not cause any visual symptoms, if you are age 50 or older, a complete eye examination by an ophthalmologist is recommended on an annual basis to look for signs of the disease, particularly if there is any history of macular degeneration in your family. Although macular degeneration reduces vision in the central part of the retina, it does not affect the eye's side or peripheral vision. For example, you could see the outline of a clock but not be able to tell what time it is.
The exact cause of dry macular degeneration is unknown, but the condition develops as the eye ages. Risk factors for AMD include age, smoking, family history of macular degeneration, gender (females are more likely to be affected by age-related macular degeneration), race (Caucasians are more likely to be affected by age-related macular degeneration than other races), prolonged sun exposure, a high fat diet, and/or one that is low in nutrients and antioxidants, obesity, high blood pressure, and light colored eyes. Macular degeneration affects the retina in two forms: dry and wet. The dry form of AMD is more common.
Most people have "dry" macular degeneration. Vision loss is usually gradual and is generally not severe. It is caused by aging and thinning of the tissues of the macula and is characterized by the presence of small, yellowish deposits under the retina, called drusen.
"Wet” or “neovascular” macular degeneration accounts for about 10% of all cases. It is caused by the growth of abnormal blood vessels underneath the retina that leak fluid or blood This leaking of fluid or blood results in blurred central vision. Vision loss may be rapid and severe. Recent advances in the treatment of wet AMD can now prevent further loss of vision or even restore vision in some cases if treatment is sought promptly.
Macular degeneration can cause different symptoms in different people. The condition may be hardly noticeable in its early stages. Sometimes only one eye loses vision while the other eye continues to see well for many years. When both eyes are affected, the loss of central vision may be noticed more quickly. The following are some common ways vision loss is detected:
Many people do not realize that they have a macular problem until blurred vision becomes obvious. Your ophthalmologist can detect early stages of macular degeneration during a medical eye examination, which may include specialized testing, such as OCT, Angiogram of the eye, and fundus photography.
Despite ongoing medical research, there is no cure yet for "dry" macular degeneration. However, many doctors believe, and some studies have suggested, that a very specific combination of nutritional supplements may slow the progression of macular degeneration. Certain patients with intermediate forms of dry AMD may benefit from a specific vitamin formulation that has been shown in clinical trials to decrease the chance of developing the more advanced stages of AMD. Please note that the Age-Related Eye Diseases Study (AREDS) tested the benefit of a defined vitamin formulation that may be different from that included in many over-the-counter supplements. You should consult with your ophthalmologist or retina specialist to verify whether you are a candidate for AREDS vitamins and to determine which formulation is right for you.
If you have the early form of AMD, studies have shown that you can reduce your chances of loss of vision by not smoking, maintaining a healthy diet including fruits and vegetables rich in antioxidants, and working with your doctors to control your blood pressure. Treatment of this condition focuses on helping a person find ways to cope with visual impairment.
There have been great strides in the treatment of the wet, or neovascular, form of AMD in the past few years. Most patients who begin to experience loss of vision as a result of the presence of abnormal new vessels in AMD can maintain stable vision or perhaps even experience improvement in vision following prompt treatment with a new class of medications which block a molecule named Vascular Endothelial Growth Factor (VEGF).
Anti-VEGF treatments seek to stop the abnormal blood vessel growth of wet AMD. The most common anti-VEGF agents used at this time include ranibizumab (Lucentis™), approved for the treatment of wet AMD by the FDA in 2006, bevacizumab (Avastin™), and EYLEA.
These medications are delivered via injection into the eye affected by neovascular AMD. Your eye will be numbed prior to the injection. After your injection, you will go home and be instructed to rest. You may want to bring a friend or family member with you to drive you home. Injections are generally performed monthly, although your retinal specialist will determine the dosing schedule that is best for you. Injections of anti-VEGF agents are performed in our office and are generally well-tolerated. Most patients are able to resume their daily activities immediately. You will be instructed to use antibiotic eye drops for several days following your injection. While anti-VEGF agents are relatively safe, there are rare associated risks. You will have the opportunity to discuss the risks and benefits of anti- VEGF treatment with your doctor. If you experience worsening vision, pain, or progressive eye irritation and redness following an injection, contact your doctor immediately.
Despite advanced medical treatment, people with macular degeneration still experience some vision loss. We can prescribe optical devices or refer you to a low-vision specialist or center. A wide range of support services and rehabilitation programs are also available to help people with macular degeneration maintain a satisfying lifestyle. Because side vision is usually not affected, a person's remaining sight can be very useful. Often, people can continue with many of their favorite activities by using low-vision optical devices such as magnifying devices, closed-circuit television, large print reading materials and talking or computerized devices