Delayed graft rejection in pre-vascularised corneas after subconjunctival injection of clodronate liposomes

Purpose. To test the effects of clodronate liposomes on graft survival and neovascularisation after transplantation in pre-vascularised recipient corn eas. Methods. Corneal neovascularisation was induced in F344 rats by injecting h eat inactivated rabbit serum intrastromally. After 4 weeks F344 rats were o rthotopically grafted with corneal buttons from DA rats. Directly after tra nsplantation and on 2, 4, 6 and 8 days postoperatively clodronate liposomes were administrated subconjunctivally in one group, whereas the other group remained untreated. For 60 days grafts were observed for signs of graft re jection and neovascularisation. Results. Graft survival was significantly prolonged, but not prevented in c lodronate liposome treated rats compared to untreated rats (p = .004). Also clodronate liposome administration delays growth of corneal neovascularisa tion after transplantation. Conclusions. Previous studies revealed that clodronate liposomes prevent co rneal graft rejection and reduce neovascularisation in orthotopic corneal a llotransplantation in rats. This study shows that also in pre-vascularised recipient corneas subconjunctival administration of clodronate liposomes se ems to delay corneal graft rejection and reduces neovascularisation.