OF ALL the infectious agents causing corneal blindness, herpes simplex virus is the most common in the United States: half a million cases of ocular herpes infection occur annually. On a worldwide basis, Chlamydia trachomatis is the most frequent cause of blindness: an estimated 6 million people are sightless because of this bacterium.
However, it may be the body's own immune response that destroys vision.
At the Research to Prevent Blindness science writers' conference in Arlington, Va, Robert L. Hendricks, PhD, of the University of Illinois (Chicago) Department of Ophthalmology, described how this was demonstrated by his group. They induced cellular immune tolerance specifically to herpes simplex virus by inoculating the anterior chamber of the eyes of mice with that virus. A control group had intact cellular immunity. The researchers infected all mice by applying a suspension of herpes simplex virus topically and rubbing it into a previously