According to a study that appears in the April 17 issue of Neurology, researchers at the University of Pennsylvania School of Medicine have found that natalizumab (TYSABRI), a drug that slows disability and reduces relapse rates in patients with multiple sclerosis (MS), also reduces vision loss in patients with relapsing MS.
Vision loss is one of the most common and disabling symptoms of MS.
"Not only does natalizumab prevent the worsening of vision loss in people with relapsing MS, but it is also associated with significant reductions in the likelihood of sustained vision loss due to inflammatory demyelination of nerve fibers that connect to the eye, a common cause of visual loss in MS," says Laura J. Balcer, MD, MSCE, Associate Professor of Neurology and Ophthalmology at Penn, and lead author of the paper.
The researchers analyzed data from two randomized, double-blind, placebo-controlled, parallel group, phase 3 clinical trials involving 2,138 men and women with relapsing MS from clinical centers in Europe, North America, Australia, and New Zealand. More than half of the participants received natalizumab every four weeks for two years, while the remaining participants received placebo. Visits were conducted every 12 weeks and visual function testing was performed at each study visit. Low-contrast letter acuity was measured using low-contrast letter charts (eye charts with gray letters on a white background).
Researchers found vision loss , a worsening of vision defined as a two-line (10-letter) reduction in letter chart scores , was reduced by as much as 47% among people taking natalizumab, compared to those taking placebo.