common eye conditions

Age-Related Macular Degeneration

What is it?

Age-related macular degeneration (ARMD or AMD) is the most common cause of vision loss in the United States. Eleven million people in the United States have some form of ARMD and that number is predicted to double by 2050. Age is a strong risk factor for ARMD with the risk being 2% for people between ages 50 and 59 but increasing to almost 30% for those over age 75.

In ARMD, the macula, the central part of the retina, is damaged. Both eyes are commonly affected. Patients do not lose their peripheral vision but the loss of central vision can take away the ability to drive or read.

There are two forms of ARMD: Dry ARMD and Wet ARMD.

In Dry ARMD, aging changes to the macula occur with the formation of deposits (Drusen). About 8 out of 10 patients with ARMD have Dry ARMD. The vision loss of Dry ARMD progresses slowly but is irreversible. Dry ARMD may develop into the the second, less common type of ARMD, Wet ARMD. In Wet ARMD, abnormal blood vessels grow under the retina and may leak blood or fluid. The vision loss of Wet ARMD is more rapid and can be sudden.

Detection

In the early stages, people may not notice any symptoms. As ARMD progresses there is noticeable distortion or blurring of vision. Often the damage is irreversible, but further worsening may be stopped with treatment.

Risk factors for ARMD are age (people over the age of 60 are at a higher risk), having a family history of ARMD, being Caucasian, and smoking.

If you are diagnosed with ARMD, you should use an Amsler grid daily to check your vision.

To use the Amsler grid, stare at the center dot and pay attention to the surrounding grid of lines.  All lines should be straight.

In ARMD, there may be a wavy or distorted area or an area may be darkened, covered, or not visible. You may have changes present already, but they should be stable. If the appearance of the Amsler grid changes from what you are used to, contact your ophthalmologist right away.

Treatment

Early detection of ARMD is important to begin treatment. Lifestyle changes including stopping smoking, control of blood pressure and cholesterol, and eating a healthy diet with green leafy vegetables and fish may help. Dietary supplements may help some patients. Later stages of Wet ARMD may be  treated with laser treatment and injections to the eye, which can decrease the chances for  further vision loss.

ARMD Surgery—Intravitreal Injections

Injections into the eye are used to treat ARMD at certain stages in its course.

The medications used are primarily anti-VEGF (vascular endothelial growth factor) drugs that act by reducing the growth of abnormal blood vessels in the retina and the leakage from these vessels that damages the retina and produces the loss in vision. The medications are injected directly into the eye and it is common to require monthly injections to control the disease.

The decisions on which patients should receive the injections, what medication to use, and when the injections need to be repeated are very complex. While the injections are given quickly and don’t cause much discomfort, only an ophthalmologist has the education and training to make the right treatment decisions and to safely administer the injections.