One-year follow-up of epithelial corneal cell sheet allografts mounted on platelet poor plasma in rabbits

PURPOSE To evaluate the usefulness of epithelial corneal sheets mounted on platelet poor plasma (PPP) for allograft transplantation of rabbits with total limbal stem cell deficiency (LSCD) and to prove its efficacy at 1 year after surgery. METHODS LSCD was induced in 21 female rabbits by mechanical keratectomy. To configure the grafts, limbal biopsies were taken from male rabbits and cells were cultured on a fibroblast feeder layer grown on clotted autologous PPP. After keratectomy, grafts were sutured over the stroma. Control groups consisted of no implant or an implant of clotted PPP. Rabbits were euthanized at 3 and 12 months. Corneas and cultured sheets were processed for histopathology and immunohistochemistry (K3/12 and K19). Gender analysis was performed at 4 and 7 months. RESULTS One rabbit had endophthalmitis, and another died of no apparent cause. The rest of the animals treated had no inflammation, showed a stratified epithelium, keratin 3/12 expression, and no expression of keratin 19. At 1 year, seven of eight rabbits showed no LSCD or corneal rejection signs. Y chromosomes were detected at 4 and 7 months postoperatively. All controls showed LSCD signs, erratic epithelium, and minimal cell differentiation; they revealed a slight expression of K3/12 and an expression of K19 in patchy patterns. CONCLUSIONS Allografts contributed to restoring a healthy eye surface without signs of graft rejection. This technique seems to be a promising procedure for bilateral ocular surface diseases and may be useful for new therapeutic strategies.