title: Two-step LASIK with topography-guided ablation to correct astigmatism after penetrating keratoplasty.
abstract: OBJECTIVE
  To assess the efficacy, predictability, stability, and safety of a two-step LASIK procedure using topography-guided ablation to correct astigmatism after penetrating keratoplasty.
  
  
  METHODS
  Fifteen eyes of 15 patients underwent a two-step LASIK procedure at the Maggiore Hospital of Bologna, Italy. In the first step, a flap was created using the Hansatome microkeratome. In the second step, topography-guided ablation using the LaserSight LSX was planned with interactive software (CIPTA) once topographical and refractive stabilization had been obtained. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cylindrical correction, gain of lines of BSCVA, spherical equivalent refraction, and complications were analyzed.
  
  
  RESULTS
  Minimum follow-up was 12 months (range: 12 to 30 months). Uncorrected visual acuity improved in all 15 (100%) eyes. At the last postoperative examination, 11 (73%) eyes had UCVA > or = 20/40. Nine (60%) eyes were within 1.0 diopter (D) of the attempted correction. Mean postoperative astigmatism was -1.67 (range: -3.5 to 0; standard deviation: 1.26). Index of success of astigmatic correction was 0.26. No patient lost Snellen lines of BSCVA. Intraoperative complications included two buttonhole flaps, and postoperative complications included one flap retraction. No further laser treatment was needed.
  
  
  CONCLUSIONS
  The two-step LASIK procedure using topography-guided ablation reduces spherical and cylindrical refractive error due to penetrating keratoplasty. Topography-guided ablation also proved to be effective in correcting irregular astigmatism.
authors.affiliation: Department of Ophthalmology, Maggiore Hospital, Bologna, Italy. alessandro.mularoni@ausl.bologna.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mularoni
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Laffi
authors.forename: Leona
authors.initials: L
authors.lastname: Bassein
authors.forename: Giorgio
authors.initials: G
authors.lastname: Tassinari
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D003316:Corneal Diseases / Q000601:surgery; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D016896:Treatment Outcome; D014792:Visual Acuity