On the survival of penetrating corneal grafts: analysis of clinical cases

Background. Selective keratoplasty techniques, in which only the affected corneal layers are replaced, are increasingly used in modern corneal transplantation. In penetrating keratoplasty (PK), however, all layers of a structurally altered cornea are replaced with a donor graft. PK remains the only surgical option for many severe anterior segment conditions, including advanced keratoconus, corneal ulcer with stromal melting and/or perforation, and corneal opacities of various origins involving the full corneal thickness. Purpose: to report clinical cases of penetrating corneal grafts with transparency preserved for more than 20 years. Materials and methods. In 2024, 19 patients (24 eyes) with penetrating corneal grafts performed by the authors more than 20 years earlier (20– 35 years) were examined. The cohort included 10 men and 9 women. In all cases, fresh (non-stored) donor corneas were used, with a death-to-surgery interval of less than 24 hours. The graft diameter was ≥8 mm in all eyes. The primary diagnosis was advanced keratoconus (stage IV by Amsler, or post-hydrops scarring) in 13 patients. The remaining six patients had dense corneal scars and opacities due to penetrating trauma, severe keratitis, or ulcers (including cases with perforation). Results. In all 24 eyes, the corneal grafts remained transparent; two cases showed progressive endothelial graft dysfunction. Five representative cases of ultra-longterm graft survival and one case of bilateral reconstructive PK performed in Minsk, Republic of Belarus (1 and 8 years post-surgery), are illustrated. Conclusion. Penetrating keratoplasty with fresh donor corneas of high endothelial cell density provides the potential for successful graft survival with long-term–and even ultra-long-term–maintenance of transparency. In keratoconus, refractive PK may result in lower post-keratoplasty ametropia, better visual function, and a reduced risk of ectasia recurrence.