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

To test the effects of clodronate liposomes on graft survival and neovascularisation after transplantation in pre-vascularised recipient corneas.

Corneal neovascularisation was induced in F344 rats by injecting heat inactivated rabbit serum intrastromally. After 4 weeks F344 rats were orthotopically grafted with corneal buttons from DA rats. Directly after transplantation 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 rejection and neovascularisation.

Graft survival was significantly prolonged, but not prevented in clodronate liposome treated rats compared to untreated rats ( p =.004). Also clodronate liposome administration delays growth of corneal neovascularisation after transplantation.

Previous studies revealed that clodronate liposomes prevent corneal graft rejection and reduce neovascularisation in orthotopic corneal allotransplantation in rats. This study shows that also in pre-vascularised recipient corneas subconjunctival administration of clodronate liposomes seems to delay corneal graft rejection and reduces neovascularisation.