People's faces look less clear to you, and words in a book seem blurry. Lately you need more light for reading. Straight lines appear wavy or crooked. Any of those changes in eyesight could signal an eye disease known as age-related macular degeneration (AMD), the leading cause of blindness and severe vision loss in older people. About 1.75 million Americans suffer from its advanced stage.

AMD can rob you of your central vision, the kind that's needed for reading, driving, and recognizing faces. Dry AMD, the more common and often less severe form occurs when the macula, the part of the retina that's responsible for central vision, slowly breaks down with age. More damaging still is wet AMD, which develops when abnormal blood vessels grow behind the retina and leak blood and fluid, often causing rapid and severe sight loss.

Fortunately retina specialists can combat wet AMD with a new class of drugs, known as VEGF inhibitors, that are injected directly into the eye to halt the growth of those blood vessels. Two drugs in that class are widely used. Ranibizumab (Lucentis) is approved by the Food and Drug Administration for the treatment of AMD, and well-designed clinical trials have found that it arrests the course of the disease and even improves vision. Bevacizumab (Avastin) is a similar drug that's approved to treat cancer by preventing the growth of blood vessels that nourish tumors. Some studies have found that when Avastin is used in the eye its effect is comparable to Lucentis, though evidence is limited to case studies and descriptive reports. Avastin hasn't been evaluated for AMD in randomized controlled trials and it's not approved to treat AMD. Yet many retina specialists use it "off label."

Which drug would you use? If the choice seems obvious, read on.