Efficacy of systemic cyclosporine A and amniotic membrane on rabbit conjunctival limbal allograft rejection

Purpose: To evaluate the effect of intramuscular cyclosporine A (CsA) and amniotic membrane (AM) on conjunctival limbal allograft survival in a rabbit model. Methods: Eighty-two female rabbits (59 New Zealand white rabbits, 23 Dutch pigmented rabbits) were used. The New Zealand white rabbits were divided into 4 treatment groups: group 1 (n = 13), conjunctival limbal autograft transplantation; group 2 (n = 12), conjunctival limbal allograft transplantation without additional treatment; group 3 (n = 18), conjunctival limbal allograft transplantation and human AM; and group 4 (n = 16), conjunctival limbal allograft transplantation and systemic CsA (10 mg/kg/day intramuscularly). The 23 Dutch pigmented rabbits were used as limbal stem cell allograft donors. The rejection index, the mean survival time, and the rejection rates were calculated for each group. Results: After 28 days of follow-up, there were no episodes of limbal rejection in groups 1 and 4, whereas the rejection rate was 100% in groups 2 and 3. There was no significant difference in mean survival time of the rejected grafts between groups 2 and 3. Conclusions: A model of rejection of conjunctival limbal transplantation was developed in the rabbit. Intramuscularly injected CsA effectively prevents limbal allograft rejection. Human AM is not useful for this purpose.