Two-step LASIK after penetrating keratoplasty

Abstract

Aris N Kollias, Markus M Schaumberger, Thomas C Kreutzer, Michael W Ulbig, Carlo A LackerbauerUniversity Eye Hospital, Ludwig-Maximilians University, Munich, GermanyPurpose: The point of interest of this retrospective case review is to study refractive changes caused by the hinged lamellar keratotomy and the refractive outcome after laser ablation in a second step within the scope of laser in situ keratomileusis (LASIK) in patients with penetrating keratoplasty.Methods: Data from eight patients obtained before lamellar keratotomy, before laser ablation, and three months later were evaluated. Keratotomies were performed with the Moria® LSK one and the Amadeus® 2 microkeratome, laser ablation was performed with the Schwind® Keratome I and the Wavelight® Allegretto WaveEyeQ. Results: Uncorrected visual acuity (UCVA) improved significantly from 1 [logMar] to 0.4 [logMar] at the last visit. Median gain of UCVA was 7.38 ± 2.96 Snellen lines. Best spectacle-corrected visual acuity did not change significantly. Preoperative manifest refraction spherical equivalent decreased from -4.02 ± 4.77 diopters (D) to -1.11 ± 2.45 D after laser ablation. Mean preoperative manifest astigmatism was -7.27 ± 3.65 D, after lamellar keratotomy -6.72 ± 3.68 D, and after laser ablation -2.08 ± 1.80 D. Manifest astigmatism did not change significantly after the keratotomy.Conclusions: Lamellar keratotomy causes biomechanical changes to the cornea. We favor a two-step LASIK in penetrating keratoplasty patients in order to improve precision and predictability of the refractive outcome.Keywords: two-step, cornea, LASIK, keratoplasty, astigmatism