A medication prescribed to limit nerve damage caused by multiple sclerosis also seems to prevent subtle vision loss in many patients.
People with multiple sclerosis (MS) experience pain, weakness, loss of muscle control, and slurred speech as a result of inflammatory damage to the fatty sheaths that insulate nerves. More than half of people with the illness also have episodes of blurry vision caused by optic neuritis, inflammation of the nerves that carry signals from the eyes to the brain.
In 2004, the Food and Drug Administration approved the drug natalizumab (Tysabri) for MS after two clinical trials found that monthly injections alleviated some MS symptoms, which flare up during relapses. In one trial, participants received either natalizumab or a placebo. In the other trial, all the participants were taking interferon beta, a standard MS drug, and also received natalizumab or a placebo.