title: Simultaneous bilateral laser in situ keratomileusis: safety and efficacy.
abstract: OBJECTIVE
  To compare the safety and efficacy of simultaneous bilateral to sequential bilateral laser in situ keratomileusis (LASIK) surgery for the correction of myopia.
  
  
  METHODS
  Retrospective, nonrandomized, comparative trial.
  
  
  METHODS
  A total of 2142 consecutive simultaneous and sequential bilateral myopic LASIK surgery eyes operated from March 1996 through June 1998 for the correction of myopia were reviewed.
  
  
  METHODS
  Two surgeons (HVG and JAV) performed myopic LASIK using the Nidek EC-5000 excimer laser and either the Chiron Automated Corneal Shaper or the Bausch & Lomb Hansatome microkeratome.
  
  
  METHODS
  The incidence of intra- or perioperative complications for sequential and simultaneous bilateral LASIK for myopia was recorded. Refractive and visual outcomes at 3 to 6 months postoperative were analyzed. Deviations from targeted spherical equivalent (SE), uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and retreatment rates are reported.
  
  
  RESULTS
  Laser in situ keratomileusis was performed on the first eye of 1853 patients scheduled for simultaneous bilateral myopic LASIK. Of these, 28 (1.5%) first eyes had intraoperative or perioperative complications. The second eye surgery was cancelled in 11 cases, and 1842 second eyes completed simultaneous surgery; 13 (0.7%) intraoperative or perioperative complications occurred. Of these 41 complications in simultaneous cases, 1 eye lost 1 line of BCVA at 6 months follow-up. Two hundred eighty-nine patients were scheduled for sequential bilateral myopic LASIK. Five (1.8%) first eyes of the sequential cases had intraoperative complications compared with four (1.4%) sequential second eyes. There was no loss of BCVA in any sequential bilateral case with complications at a minimum at 6 months follow-up. There was no statistically significant difference between intra- and perioperative complication rates comparing simultaneous to sequential bilateral LASIK. Three to 6 months postoperative visual and refractive data were reviewed; except when comparing simultaneous first eye postoperative SE to sequential first eye, there was no statistically significant difference in refractive or visual outcomes, including deviation from targeted SE, UCVA, BCVA, and retreatment rates.
  
  
  CONCLUSIONS
  Simultaneous bilateral LASIK is as safe and effective as sequential surgery. Simultaneous bilateral LASIK may offer several benefits to the patient.
authors.affiliation: Gimbel Eye Centre, Calgary, Alberta, Canada. hvgimbel@gimbel.com
authors.forename: H V
authors.initials: HV
authors.lastname: Gimbel
authors.forename: J A
authors.initials: JA
authors.lastname: van Westenbrugge
authors.forename: E E
authors.initials: EE
authors.lastname: Penno
authors.forename: M
authors.initials: M
authors.lastname: Ferensowicz
authors.forename: G A
authors.initials: GA
authors.lastname: Feinerman
authors.forename: R
authors.initials: R
authors.lastname: Chen
mesh_terms: D000328:Adult; D003315:Cornea / Q000601:surgery*; D016039:Corneal Transplantation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D009216:Myopia / Q000601:surgery*; D011183:Postoperative Complications; D012029:Refraction, Ocular; D012189:Retrospective Studies; D012449:Safety; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity