Ocular Surface Stem Cell Transplantation Rejection: Incidence, Characteristics, and Outcomes

Purpose: To describe the incidence, characteristics, risk factors, treatment, and outcomes of ocular surface stem cell transplantation (OSST) rejection. Methods: A chart review of patients who had OSST at a single institution between 1998 and 2010 was performed. Data were collected on patient demographics, type of OSST procedure, duration of immunosuppression, and rejection characteristics. Main outcome measures were ocular surface stability and improvement in best-corrected visual acuity. Results: Two hundred twenty-two eyes of 158 patients were included with mean follow-up of 62.7 months (range, 12.0-158.3 months). The most common indications for OSST were aniridia (46.4%), chemical/thermal injury (22.1%), and Stevens-Johnson syndrome (12.2%). The most common procedures performed were keratolimbal allograft (KLAL) alone (80.6%) and combined living-related conjunctival allograft (lr-CLAL)-KLAL (11.3%). Mean time on immunosuppression was 44.3 months (range, 7.6-138.2 months). Severe rejection occurred in 43 eyes (19.4%) with mean time to rejection being 15.2 months (range, 0.2-93.1 months). Low-grade rejection occurred in 26 eyes (11.7%) with mean time to rejection being 26.2 months (range, 1.3-64.9 months). At the final follow-up, 36.6% of eyes in the rejection group achieved a stable ocular surface compared with 71.9% of eyes in the nonrejection group (P < 0.0001). Risk factors associated with increased risk of rejection were younger age (P < 0.0001), KLAL alone (P = 0.049), and noncompliance with immunosuppression (P = 0.047). Conclusions: Ocular surface outcomes for patients with OSST rejection are poor, with the majority of patients having failed ocular surfaces despite treatment with increased immunosuppression and repeat OSST. It is critical for success that OSST patients are closely monitored for rejection and for compliance with immunosuppression.