title: Long-term visual and refractive outcomes following surface ablation techniques in a large population for myopia correction.
abstract: OBJECTIVE
  To evaluate the visual and refractive outcome for four wavefront-guided surface ablation (WGSA) techniques (LASEK, LASEK flap-off [LASEK FO], Epi-LASIK, and Epi-LASIK flap-off [Epi-LASIK FO]) in a large myopic population.
  
  
  METHODS
  This retrospective review included 1000 myopic eyes (spherical equivalent [SE] -1.0 to -8.0 diopters [D]) treated with WGSA (VISX STAR S4 with IR) using four different epithelial management techniques. Flaps were either retained (163 Epi-LASIK, 361 LASEK) or discarded (277 Epi-LASIK FO, 199 LASEK FO). Eyes in each group were stratified to either low, mild, moderate, or high myopia based on preoperative SE. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), predictability, lines lost, and haze were compared at 3, 6, and 12 months.
  
  
  RESULTS
  At 1 year, UDVA and CDVA of ≥20/20 and 20/15 were comparable across the four procedure groups and within each subgroup of myopia. Predictability was less than or equal to ±0.5 D of intended correction in 96% to 99% of eyes. LASEK FO and Epi-LASIK FO outperformed the EPI-LASIK in achieved MRSE, especially in the high myopia category (-0.012, 0.040, and -0.27 D, respectively, P < 0.05). No eyes lost more than one line of CDVA; and 50% to 60% of eyes in each group gained one or more lines. No significant haze was recorded in any group. There was no statistically significant difference between groups in the preoperative MRSE and efficacy indices except for LASEK FO.
  
  
  CONCLUSIONS
  At 1 year, there was no statistically significant difference in visual outcomes between techniques for any degree of myopia. However, the MRSE achieved with LASEK FO and Epi-LASIK FO were closer to emmetropia.
authors.affiliation: Ottawa Hospital Research Institute, Ontario, Canada.
authors.forename: Sadhana V
authors.initials: SV
authors.lastname: Kulkarni
authors.forename: Tahra
authors.initials: T
authors.lastname: AlMahmoud
authors.forename: David
authors.initials: D
authors.lastname: Priest
authors.forename: Sabrina E J
authors.initials: SE
authors.lastname: Taylor
authors.forename: George
authors.initials: G
authors.lastname: Mintsioulis
authors.forename: W Bruce
authors.initials: WB
authors.lastname: Jackson
mesh_terms: D000328:Adult; D063171:Corneal Pachymetry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000145:classification / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult