title: Comparison of in vivo confocal microscopic findings between epi-LASIK procedures with different management of the epithelial flaps.
abstract: OBJECTIVE
  To use in vivo confocal microscopy to compare the wound-healing process in epikeratome laser-assisted in situ keratomileusis (epi-LASIK) with different management of the epithelial flaps.
  
  
  METHODS
  This prospective study comprised 46 eyes in the on-flap group and 47 eyes in the off-flap group. Epithelial flaps were repositioned or removed in the on- and off-flap eyes, respectively. In vivo confocal microscopy was performed before surgery and at 1 and 2 weeks and 1, 3, and 6 months after surgery. Corneal epithelial thickness, basal/apical surface epithelial morphology, and stromal reactions were analyzed.
  
  
  RESULTS
  Complete epithelialization by slit lamp biomicroscopy was faster for mitomycin C (MMC)-treated off-flap (4.27 ± 0.70 days) than on-flap (5.84 ± 0.08 days) eyes (P = 0.01). The percentage of eyes recovering to preoperative basal epithelial cell confocal morphology in the on- and off-flap groups was 87.5% and 92.3% for MMC-treated eyes and 86.3% and 90.5% in eyes without MMC treatment at 1 month after surgery. Of the studied eyes, with or without MMC, 50% and 100% returned to their preoperative apical epithelial morphology by 3 months in the on-flap and off-flap groups, respectively. Regression analysis revealed that the repositioned flap resulted in significant delay of epithelialization and apical-basal epithelial recovery (P < 0.01). Stromal reaction did not differ significantly at any of the time points. Corneal epithelial thickness was significantly thicker in the on-flap eyes (54.2 ± 4.5 μm) than in the off-flap eyes (26.7 ± 5.8 μm) at 1 month after surgery (P < 0.01).
  
  
  CONCLUSIONS
  On- and off-flap epi-LASIK showed comparable clinical outcomes after surgery. Off-flap epi-LASIK had more rapid re-epithelialization and normalization of epithelial morphology than did on-flap epi-LASIK, when observed by in vivo confocal microscopy. (ClinicalTrials.gov number, NCT00491439.).
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Chen
authors.forename: Elizabeth P
authors.initials: EP
authors.lastname: Shen
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Hsieh
authors.forename: Po-Ting
authors.initials: PT
authors.lastname: Yeh
authors.forename: Tsung-Jen
authors.initials: TJ
authors.lastname: Wang
authors.forename: Fung-Rong
authors.initials: FR
authors.lastname: Hu
mesh_terms: D000328:Adult; D000477:Alkylating Agents / Q000008:administration & dosage; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D019573:Epithelium, Corneal / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage; D009216:Myopia / Q000503:physiopathology / Q000601:surgery; D011446:Prospective Studies; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*; D055815:Young Adult
chemical_list: D000477:Alkylating Agents; D016685:Mitomycin