Cyclosporine-containing collagen shields suppress corneal allograft rejection.

Thirty-seven rabbit eyes with penetrating keratoplasty grafts placed in vascularized beds to enhance the possibility of graft rejection were treated with cyclosporine delivered in collagen shields or drops of olive oil. Treatment was begun either immediately after grafting or at the first sign of immune graft reaction. Mean survival time of the grafts in the collagen shield treated eyes was significantly longer than in the eyes treated with drops. In the eyes treated at the first sign of graft reaction, cyclosporine in collagen shields halted the rejection process; seven of these eyes survived the 120-day observation period, compared to one of the eyes treated with drops. These results indicate that the collagen shield is an effective delivery system for cyclosporine and the topically administered cyclosporine is effective in suppressing the initiation of graft rejection and in reversing a graft reaction in progress.