Femtosecond Laser-Assisted Keratoplasty: A Narrative Review of Technological Evolution, Clinical Evidence, Implementation and Future Directions

Abstract: Femtosecond laser-assisted keratoplasty (FLAK) enables programmable photodisruption, customized graft-host configurations, and image-guided corneal reconstruction. This narrative review synthesizes 107 scholarly publications spanning 2003– 2026, identified through PubMed/MEDLINE and reference lists, alongside regulatory documentation. It examines mechanisms, technological development, clinical evidence, emerging approaches, and implementation. Evidence is interpreted primarily through final best-corrected visual acuity, graft survival, and reintervention, with incision precision treated as a surrogate. In penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK), femtosecond laser (FSL) assistance may improve wound architecture and selected early outcomes, but durable patient-relevant superiority remains unproven. Randomized endothelial keratoplasty evidence identified poorer visual acuity and greater endothelial loss with early FSL-assisted donor preparation, despite reduced astigmatism. Selected Descemet membrane endothelial keratoplasty (DMEK) and reconstructive applications remain promising but insufficiently validated. Emerging approaches include stromal lenticule repair, additive reconstruction, limbal transplantation, and scaffold preparation. Their evaluation must separate procedural feasibility from comparative effectiveness. Postoperative healing, suture management, complications, and surgical experience can outweigh initial geometric precision. Historical economic evidence disfavors FSL-assisted endothelial graft preparation; contemporary cost-effectiveness remains uncertain. Selective implementation should consider clinical need, local expertise, shared infrastructure, and equitable access. Future evaluation should prioritize long-term patient outcomes, direct economic comparisons, and multicenter validation of lower-energy platforms, real-time imaging, artificial intelligence-assisted planning, and biomechanically informed incision design. Keywords: corneal transplantation, femtosecond lasers, penetrating keratoplasty, endothelial keratoplasty, lamellar keratoplasty, corneal stroma