Outcomes of allogeneic ocular surface stem cell transplantation

Allogeneic ocular surface stem cell transplantation (OSST) is an established therapeutic approach for limbal stem cell deficiency, utilizing techniques such as keratolimbal allograft (KLAL), living-related conjunctival limbal allograft (lr-CLAL), allogeneic cultivated limbal epithelial transplantation (allo-CLET), and allogeneic simple limbal epithelial transplantation (allo-SLET). This review synthesizes evidence from 35 studies encompassing 1, 268 eyes with at least 24 months of follow-up to evaluate intermediate- and long-term outcomes. Overall, OSST is associated with improvement in visual acuity and restoration of ocular surface stability, although success rates vary widely by technique, ranging from 13% to 87%. Outcomes appear to be influenced by the intensity of systemic immunosuppression, with triple-agent regimens demonstrating higher rates of long-term success compared with single- or dual-agent approaches. Among techniques, lr-CLAL may offer advantages over KLAL due to lower rejection rates. Despite encouraging results, long-term data remain limited for newer approaches such as allo-CLET and allo-SLET. Careful postoperative monitoring and management of complications, including rejection, glaucoma, and microbial keratitis, remain essential to optimize outcomes.