Purpose: Corneal graft rejection suppression after intramus-cular cyclosporine administration at different periods of time was studied on a penetrating keratoplasty rejection model in the rat. Methods: Inbred Lewis rats were used as recipients and Fischer rats were used as donors in a orthotopic rejection model of corneal transplantation. Intramuscular injection of cyclosporine 10 mg/kg per day was administered up to the 30th postoperative day in 3 groups with different starting periods: at the day of surgery, at the 7th , and at the 9th postoperative day. Grafts were evaluated through clinical and histological examination. Results: The corneal grafts developed a 100% rejection in about 3 weeks after the penetrating keratoplasty in the control group (n = 5) in which no cyclosporine was adminis-tered. Graft rejection was detected in one case in the groups in which cyclosporine was administered (n = 15), but the process was inhibited during the study period. Histological studies confirmed the clinical evaluations. Conclusions: These data indicate that intramuscular cyclosporine may control the corneal graft rejection, even during the active phase.
Cyclosporine A; Keratoplasty; experimental penetrating; Graft rejection