Age-related macular degeneration is the leading cause of blindness in people over 65 years old in the United States. It is a condition involving the macula, the center part of the retina which leads to loss of detailed vision. When the macula is affected, an individual may have difficulty reading, driving, seeing faces, threading a needle or seeing small objects like salt crystals in a saltshaker. Other symptoms include distorted vision and “photo-stress response” like snow blindness or sun blindness as a reaction to bright light.
There are two forms of macular degeneration, a dry form and a wet form. The wet form is sometimes treatable with laser surgery. A new form of treatment called photodynamic therapy (PDT) has recently become available, and early detection is important to maximize chances of effective treatment.
Symptoms of Macular Degeneration
- Early macular degeneration may cause little, if any noticeable change in vision
- Difficulty reading without extra light and magnification
- Seeing objects as distorted or blurred, or abnormal in shape, size or color
- The perception that objects “jump” when you try to look right at them
- Difficulty seeing clearly enough to read or drive
- Inability to see details
- Blind spot in center of vision
Are you at Risk?
While the root causes of macular degeneration are still unknown, we do know that women are at a slightly higher risk than men, and Caucasians are more likely to develop macular degeneration than African Americans.
Macular degeneration is the leading cause of decreased vision in people over 65 years of age, and appears to be hereditary in some families but not in others. You are at an increased risk if you have experienced long-term sun exposure, if you have high blood pressure, high cholesterol, diabetes, nutritional deficiencies or if you have suffered from a head injury or infection. Smoking also increasing the risk of macular degeneration.
Diagnosing Macular Degeneration
Regular eye exams are important to determine if a person is at risk for macular degeneration and early detection may increase the chance of effective treatment. The doctors at KE Eye Centers of Texas can identify changes in the macula by looking into your eyes with various instruments, and a chart known as an Amsler Grid can be used to pick up subtle changes in vision.
Angiography is the most widely used macular degeneration diagnostic test. During the test, a harmless red-orange dye called Fluorescein will be injected into a vein in the arm. The dye will travel through the body, eventually making its way to the blood vessels in the retina. A special camera will take multiple photographs and the pictures will be analyzed to identify atypical new blood vessels or damage to the retina’s lining. The formation of new blood vessels from blood vessels in and under the macula is often the first physical sign that macular degeneration may develop.
A test known as Optical Coherence Tomography (OCT) uses light waves to create a contour map of the retina, which can show areas of thickening or fluid accumulation.
Treating Macular Degeneration
In many cases, low vision evaluation and rehabilitation can improve function in individuals affected with macular degeneration. Optical aids, including strong reading glasses, magnifying glasses and telescopes, can be very useful, as can non-optical aids such as large print periodicals and checkbooks, enlarged reading and writing guides for books or envelopes, large numeric telephone dials which adapt to a variety of phones, and audio books. A variety of support groups are also available for an increasing number of senior citizens affected with macular degeneration.
In the early stages of macular degeneration, regular eye exams, attention to diet, in-home monitoring of vision and nutritional supplements, when necessary, may be all that is recommended.
There has been active research on the use of vitamins and nutritional supplements called antioxidants to prevent or slow down the progression of macular degeneration. Antioxidants are thought to protect against the damaging effects of oxygen-charged molecules called free radicals. A potentially important group of antioxidants called carotenoids are the pigments that give fruits and vegetables their color. Two carotenoids that occur naturally in the macula are lutein and zeaxanthin.
Some research studies suggest that people who have diets high in lutein and zeaxanthin may have a lower risk of developing macular degeneration. Kale, raw spinach and collard greens are vegetables with the highest amount of lutein and zeaxanthin, and nutritional supplements that are high in these and other antioxidants are also commercially available.
In rare cases of wet macular degeneration, laser treatment may be recommended. This involves the use of painless laser light to destroy abnormal, leaking blood vessels under the retina. This form of treatment is only possible when the abnormal blood vessels are far enough away from the macula that it will not damage it. Only rare cases of wet macular degeneration meet these criteria, but when laser treatment is possible, it may slow or stop the progression of the disease but it is generally not expected to bring back any vision that has already been lost.
A relatively new form of treatment for some cases of wet macular degeneration is called photodynamic therapy, or PDT. In those cases where PDT is appropriate, slowing of the loss of vision and sometimes even improvement in vision is possible.
If you are over the age of 65, you should have an annual ophthalmologic examination at KE Eye Centers of Texas. Our ophthalmologists can tell you whether you show any signs of age-related macular degeneration.