Comparison of the long-term clinical outcomes of penetrating keratoplasty using a manual trephine and femtosecond-laser trephination

Purpose: We compare the clinical outcomes of femtosecond-laser penetrating keratoplasty and penetrating keratoplasty performed using a manual trephine. Methods: The clinical outcomes of 21 eyes that underwent penetrating keratoplasty using a manual trephine and 29 eyes that underwent femtosecond-laser penetrating keratoplasty were compared in terms of best-corrected visual acuity, refractive and corneal astigmatisms, endothelial cell counts, and graft rejection and failure. Results: The best-corrected visual acuities measured 1, 3, 6, 12, and 18 months after surgery were logMAR 1.21, 1.28, 1.25, 1.14, and 1.43 for the manual trephine group and logMAR 0.82, 0.71, 0.78, 0.49, and 0.56 for the femtosecond-laser group; the latter group thus exhibited better visual acuity at all times. The refractive astigmatism values were 5.13, 6.35, 5.28, 5.18, and 6.36 diopters (D) for the manual trephine group and 6.09, 6.33, 5.14, 5.23, and 4.89 D for the femtosecond-laser group. The corneal astigmatism values were 5.40, 6.45, 6.30, 5.64, and 5.78 D for the manual trephine group and 6.17, 6.24, 5.72, 5.02, and 4.83 D for the femtosecond-laser group. The refractive astigmatism was significantly lower at 18 months after surgery and the corneal astigmatism was significantly lower at both 12 and 18 months after surgery in the femtosecond-laser group. None of endothelial cell count, graft rejection or failure rate, differed significantly between the two groups. Conclusions: Femtosecond-laser-enabled keratoplasty affords better visual recovery, less refractive and corneal astigmatism, and better wound stability than does penetrating keratoplasty using a manual trephine.