Macular degeneration is a disease of the macula, an area of the retina at the back of the eye that is responsible for fine detail vision. Vision loss usually occurs gradually and typically affects both eyes at different rates. Even with a loss of central vision, however, color vision and peripheral vision may remain clear.
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 to read or drive
- Inability to see details
- Blind spot in center of vision
There are two forms of age-related macular degeneration, wet and dry.
Dry macular degeneration
The vast majority of cases of macular degeneration are the dry type, in which there is thinning or deterioration of the tissues of the macula or the formation of abnormal yellow deposits called drusen. Progression of dry macular degeneration occurs very slowly and does not always affect both eyes equally. Sometimes dry macular degeneration progresses to wet macular degeneration. Your doctor can discuss this with you during an exam.
Wet macular degeneration
Wet macular degeneration occurs when abnormal or leaking blood vessels grow underneath the retina in the area of the macula. These changes can lead to distorted or blurred vision and, in some cases, a rapid and severe loss of straight ahead vision.
Causes of or contributing factors to macular degeneration:
The root causes of macular degeneration are still unknown. Women are at a slightly higher risk than men. Caucasians are more likely to develop macular degeneration than African Americans.
- Age: Macular degeneration is the leading cause of decreased vision in people over 65 years of age.
- Heredity: Macular degeneration appears to be hereditary in some families but not in others
- Long-term sun exposure
- High blood pressure
- High cholesterol
- Nutritional deficiencies
- Head injury
Diagnosing macular degeneration:
Your eye doctor can identify changes of the macula by looking into your eyes with various instruments. A chart known as an Amsler Grid can be used to pick up subtle changes in vision.
Please go to Patient Forms to download the Amsler Grid test and receive instructions on how to test your vision at home.
Optical Coherence Tomography (OCT) uses light waves to create a contour map of the retina and can show areas of thickening or fluid accumulation. The OCT assists in early detection and diagnosis of retinal conditions including macular degeneration, diabetic retinopathy and glaucoma by providing high-resolution cross sectional images of the retina structures. Using this scanner, doctors can more specifically diagnose, treat and manage these conditions. The OCT technology is non-invasive and does not require exposure to painful, high intensity light, which means patient safety and comfort are optimized. Your doctor may also perform a test called an angiogram, during which a harmless dye called Fluorescein is injected into the arm. The dye will travel through your body to the blood vessels in your retina. Using a special camera, your doctor will take multiple photographs of your eye. The images will be analyzed to identify any damage to the lining of the retina or atypical new blood vessels. The formation of new blood vessels in and under the macula is often the first physical sign that macular degeneration may develop.
Treatment for macular degeneration:
In the early stages of macular degeneration, regular eye check-ups, attention to diet, in-home monitoring of vision and possibly nutritional supplements may be all that is recommended.
Diet and nutritional supplements
There has been active research on the use of vitamins and nutritional supplements called antioxidants to try to prevent or slow macular degeneration. Antioxidants are thought to protect against the damaging effects of oxygen-charged molecules called free radicals. A potentially important group of antioxidants are called carotenoids. These 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. You can also buy nutritional supplements that are high in these and other antioxidants. Ask your doctor if these vegetables or nutritional supplements are recommended for you before adding them to your diet, especially if you take anticoagulants such as warfarin. Anyone taking anticoagulants such as warfarin should avoid kale because the high level of vitamin K may interfere with the drugs. Consult your doctor before adding kale to your diet.
Lucentis, Eylea, and Avastin are newer treatments for the wet form of age-related macular degeneration which block abnormal blood vessel growth and leakage. These medications are administered via injection in the eye, which is done on an out-patient basis. Your physician may recommend a treatment protocol which includes one of these agents, depending on your individual diagnosis and condition.
In rare cases of wet macular degeneration, laser treatment or Photodynamic Therapy (PDT) may be recommended. This involves the use of painless laser light to destroy abnormal, leaking blood vessels under the retina.
Low Vision Aids
Low vision aids may help make it easier to live with the decreased vision which many people experience as a result of macular degeneration. You may be referred to the Low Vision Center (not affiliated with Asheville Eye Associates), which offers a range of support services for people with low vision. The center includes a store where clients can try out different types of vision aids to find options that match their needs. Vision enhancement devices such as assistive technology software, closed circuit (cc) TVs, electronic magnifying systems, scan and read devices, touch sensitive equipment, and high quality magnifiers are available for evaluation and may be purchased. Simple lifestyle aids such as large print books, an audio library of books for loan and a range of hand held magnifiers are also available. The Center also offers a support group for people with low vision, an occupational therapist and optometric services.