title: Wavefront-guided ablation retreatment using Iris registration.
abstract: OBJECTIVE
  To evaluate the efficacy, predictability, safety, and intraoperative and postoperative complications of laser in situ keratomileusis (LASIK) retreatment in myopic eyes using wavefront-guided ablation with iris registration (IR).
  
  
  METHODS
  Retrospective analysis was used to evaluate wavefront-guided retreatment with IR in a consecutive cohort of 77 eyes (57 patients) after LASIK. The eyes were divided into two groups: no previous retreatment group (group 1) (n = 63) and previous LASIK retreatment group (group 2) (n = 14). The primary outcome variables assessed postoperatively at 1, 3, and 6 months were uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and pre- and postretreatment changes in manifest refraction.
  
  
  RESULTS
  The mean preretreatment spherical equivalent in group 1 was reduced from -0.5 +/- 1.0 diopter (D) (range -3 to 2.4) to 0.06 +/- 0.3 (range -0.9 to 0.6) (P < 0.002) at 6 months. In group 2, the mean preretreatment spherical equivalent was reduced from -0.9 +/- 1.24D (range -3.1 to -0.5) to 0.04 +/- 0.5 (range -1.0 to 1.1) (P < 0.049) at 6 months. At 6 months, UCVA was 20/20 or better in 92% in group 1 and 64% in group 2, of patients, respectively. No eyes lost more than one line of BCVA in group 1 and one eye (7%) lost two lines of BCVA in group 2.
  
  
  CONCLUSIONS
  Wavefront-guided LASIK retreatment with IR after LASIK is an effective, predictable, and safe procedure in cases requiring a single retreatment. In contrast, eyes with previous retreatments showed less predictability and lower percentage of eyes with postoperative 20/20 UCVA.
authors.affiliation: Ophthalmology Department, Faculty of Medicine, Sohag University, Sohag, Egypt.
authors.forename: Engy M
authors.initials: EM
authors.lastname: Mohamed
authors.forename: Orkun
authors.initials: O
authors.lastname: Muftuoglu
authors.forename: Wayne
authors.initials: W
authors.lastname: Bowman
authors.forename: H Dwight
authors.initials: HD
authors.lastname: Cavanagh
authors.forename: Vinod V
authors.initials: VV
authors.lastname: Mootha
authors.forename: Gamal A
authors.initials: GA
authors.lastname: Radwan
authors.forename: James P
authors.initials: JP
authors.lastname: McCulley
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007498:Iris / Q000166:cytology*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D012029:Refraction, Ocular; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult