Prophylactic topical cyclosporine in experimental herpetic stromal keratitis

We determined the anti-inflammatory prophylactic effect of topical cyclosporine in a rabbit model of herpetic stromal keratitis. In a first study, we established that presensitization of rabbits prior to corneal intrastromal injection of herpes simplex virus produced a severe stromal keratitis beginning on day 7 after the intrastromal challenge. Twenty-four presensitized rabbits were thereafter divided into three groups for topical treatment five times a day: (1) 1% cyclosporine in a vehicle solution, started on day 4 after intrastromal challenge, plus 1% trifluridine started on day 7 after challenge, (2) the vehicle solution for cyclosporine, started on day 4, plus 1% trifluridine started on day 7, and (3) the vehicle solution for cyclosporine alone, started on day 4. The severity of stromal disease was significantly decreased in eyes treated with combined cyclosporine-trifluridine, whereas trifluridine alone had no effect on the stromal disease. Epithelial disease did not seem to be worse in eyes treated with combined cyclosporine-trifluridine; the incidence and duration of positive cultures, however, were increased in this group.