December 17, 2010
Dear Mayo Clinic:
My mother has been diagnosed with macular degeneration. Will she go blind? Am I at risk?
Macular degeneration affects the center of the retina in the back of the eye, which is called the macula. In essence, the support system underneath the retina wears out. As a result, the overlying retina begins to lose its capacity to see well. The center of the field of vision is affected in one or both eyes.
In the early stages, patients may complain of blurred vision. They sometimes notice that straight edges look distorted or crooked. In the later stages, patients may see a gray or black spot in the center of their eyesight.
Although macular degeneration is a serious condition, it doesn't cause total blindness. The majority of people diagnosed with this condition have slow, progressive degeneration, which we call dry macular degeneration. Many have good vision throughout their lives and experience only subtle, mild changes.
About 10 percent will develop wet macular degeneration, which occurs when blood vessels behind the retina break and bleed. Because of this leaking and associated retinal swelling, vision loss can be more severe.
Macular degeneration occurs later in life, generally after age 70. It is unusual to see signs of the condition earlier. There is some genetic component in terms of the risk of developing macular degeneration, especially in the rare instance of wet macular degeneration, where often both eyes are affected. But the inheritance pattern is variable, and currently unpredictable.
In the last five years, we've seen impressive breakthroughs in the treatment of wet macular degeneration. Medications injected directly into the eye shrink blood vessels to significantly improve vision and protect against further vision loss. In some cases, these injections need to be repeated.
There are not many treatments for dry macular degeneration. Research by the National Eye Institute suggests that a high-dose formulation of antioxidant vitamins, as well as the minerals zinc and copper, can slow down retinal changes. Some newer formulations contain lutein as well.
The data is less clear on whether antioxidants work as a preventive measure. But for people in their 50s or 60s who have a strong family history of macular degeneration, I usually suggest they get some antioxidants into their diet as a precaution. The best way is to include more fruits and vegetables, especially leafy, dark green vegetables, in your diet. But you can also take supplements.
Regular eye exams every year or two will screen for macular degeneration as well as glaucoma and cataracts. And, in the meantime, you can manage your health by maintaining a healthy weight, eating a healthy diet that includes fish as well as fruits and vegetables, and by following your doctor's instructions if you're being treated for cardiovascular disease or high blood pressure.
Whether sun exposure plays a part in macular degeneration has not been determined. I tell my patients to wear sunglasses if they're going to be outdoors a lot. But one definite risk factor is smoking, which has been associated with a worsening or exacerbation of macular degeneration. So if you are a smoker, that's another reason to quit.
— Saiyid Hasan, M.D., Ophthalmology, Mayo Clinic, Jacksonville, Fla.