title: Two-step LASIK after penetrating keratoplasty.
abstract: OBJECTIVE
  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((R)) LSK one and the Amadeus((R)) 2 microkeratome, laser ablation was performed with the Schwind((R)) Keratome I and the Wavelight((R)) 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.
authors.affiliation: University Eye Hospital, Ludwig-Maximilians University, Munich, Germany.
authors.forename: Aris N
authors.initials: AN
authors.lastname: Kollias
authors.forename: Markus M
authors.initials: MM
authors.lastname: Schaumberger
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Kreutzer
authors.forename: Michael W
authors.initials: MW
authors.lastname: Ulbig
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Lackerbauer