PERIOCULAR FK-506 DELAYS ALLOGRAFT-REJECTION IN RAT PENETRATING KERATOPLASTY

FK-506 is a new immunosuppressant with the ability to inhibit activati on of T-lymphocytes that would be cytolytic to an allograft. We studie d periocular injection of FK-506 in a rat penetrating keratoplasty mod el. Corneas were transplanted from Brown Norway rats into Lewis rat re cipients. The transplanted rats received periocular injection of eithe r 0.5 mg/kg FK-506 or an equivalent volume of FK-506 vehicle only. Inj ections were given 1 day before, at keratoplasty, and every other day after keratoplasty until allograft rejection. The group receiving FK50 6 had a significant delay in allograft rejection (p < 0.05). The FK-50 6 group rejected 12-20 days postkeratoplasty with a mean rejection tim e (MRT) of 14.3 days, compared with 8-14 days (MRT 11.1 days) for the control group. We conclude that periocular administration of FK506 is effective in prolonging allograft survival in the rat penetrating kera toplasty model.