title: Myopic and hyperopic laser in situ keratomileusis retreatments: indications, techniques, limitations, and results.
abstract: OBJECTIVE
  To assess the efficacy of myopic and hyperopic laser in situ keratomileusis (LASIK) retreatment procedures.
  
  
  METHODS
  Mater Private Hospital, Dublin, Ireland.
  
  
  METHODS
  Retreatment was defined as either lifting the previously created flap or when this was not possible, cutting a new flap. Fifty-six patients were retreated, 17 with hyperopia (Group 1) and 39 with myopia (Group 2). The mean preoperative spherical equivalent in Group 1 was +3.79 diopters (D) +/- 1.53 (SD) (range +1.75 to +8.12 D) and in Group 2, -5.46 +/- 2.87 D (range -0.38 to -15.25 D).
  
  
  RESULTS
  The indications for retreatment were undercorrection, decentration, epithelial ingrowth, and central island. Postoperatively, the mean spherical equivalents in Groups 1 and 2 were +1.11 +/- 2.02 D (range -1.75 to +5.50 D) and -1.02 +/- 2.20 D (range +4.75 to -9.00 D), respectively. In Group 1, the uncorrected visual acuity (UCVA) was 6/12 or better in 5.8% preoperatively and in 35% postoperatively. In Group 2, the UCVA was 6/12 or better in 5.1% preoperatively and in 59.0% postoperatively. Although 29% of the hyperopic eyes and 8% of the myopic eyes lost 1 Snellen line of best corrected visual acuity (BCVA), there was an improvement (of 1 or more lines) in BCVA in 12% and 49%, respectively. In cases that were decentered preoperatively, the postoperative optical zone ablation centration was better in 85.7% of Group 1 eyes and 61.5% of Group 2 eyes. Corneal complications following retreatment included peripheral scarring, epithelial ingrowth, Bowman's folds, and keratectasia.
  
  
  CONCLUSIONS
  Both myopic and hyperopic retreatments resulted in a stable refractive outcome. Myopic retreatments were superior to hyperopic retreatments in both efficacy and safety.
authors.affiliation: Department of Ophthalmology, Mater Private Hospital, Dublin, Ireland. mgm@ireland.com
authors.forename: M G
authors.initials: MG
authors.lastname: Mulhern
authors.forename: P I
authors.initials: PI
authors.lastname: Condon
authors.forename: M
authors.initials: M
authors.lastname: O'Keefe
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000175:diagnosis / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D009216:Myopia / Q000175:diagnosis / Q000601:surgery*; D012029:Refraction, Ocular; D012086:Reoperation; D016896:Treatment Outcome; D014792:Visual Acuity