EFFECT OF FK-506 ADMINISTERED TONICALLY VERSUS INTRAMUSCULARLY ON SUPPRESSION OF THE CORNEAL IMMUNE-REACTION IN RATS

The immunosuppressive effect of FK 506 on penetrating keratoplasty in rats was evaluated following intramuscular and topical administration, Implanted corneal grafts were inspected weekly by clinical evaluation for 3 weeks. Cytotoxic T lymphocyte (CTL) activity was measured in th e spleen on postoperative day 21, and the grafts were examined histolo gically. A dose of FK 506, 0.1 mg/kg given intramuscularly, only moder ately suppressed CTL activity and the graft failed. In contrast, doses of either 0.024 mg/day topically or 0.3 mg/kg intramuscularly suppres sed CTL activity and the grafts remained intact. Results suggest that FK 506 administered topically would be effective in preventing failure of human corneal grafts.