Utilization of Residual Donor Tissue for Regrafting in Bullous Keratopathy After Corneal Transplantation

Postoperative endothelial cell loss following Descemet stripping endothelial keratoplasty (DSEK) remains a well-recognized clinical concern, with long-term follow-up demonstrating approximately 50% reduction in endothelial cell density by 5 years. Compounding this challenge, the critical shortage of corneal donors has severely limited the expansion of corneal transplantation programs in developing countries. In conventional penetrating keratoplasty, only the central 7-mm optical zone is typically harvested, whereas the peripheral donor tissue-whose endothelial cells are believed to exhibit superior viability-is routinely discarded. To address these limitations, we describe the first-in-human use of three residual peripheral donor tissue segments, obtained after conventional keratoplasty, which were combined to perform corneal endothelial transplantation. This innovative approach substantially enhanced donor tissue utilization. Postoperatively, the patient achieved sustained corneal transparency with visual acuity improving from 20/500 to 20/50. Notably, the intersegmental gaps resolved progressively over time. Extending this proof-of-concept case, we subsequently investigated the long-term stability and safety of residual donor tissue endothelial keratoplasty for bullous keratopathy, with comprehensive evaluation of postoperative visual acuity, intraocular pressure, corneal endothelial cell density, and refractive outcomes. This study aims to establish evidence-based support for the safety and efficacy of utilizing residual graft tissue in corneal endothelial transplantation.