title: Mechanical versus alcohol-assisted epithelial debridement during photorefractive keratectomy: a confocal microscopic clinical trial.
abstract: OBJECTIVE
  To compare the effects of mechanical versus alcohol-assisted epithelial debridement on corneal cellular elements after photorefractive keratectomy (PRK) using confocal microscopy.
  
  
  METHODS
  This randomized, clinical trial included 66 eyes from 33 patients with spherical equivalent refraction <-4.00 diopters (D). Mechanical versus alcohol-assisted epithelial debridement was performed during PRK. The right eye of each patient was randomly assigned to one group (mechanical group or alcohol-assisted group) and the fellow eye to the alternate group. Confocal examination was performed preoperatively and at 3 and 6 months postoperatively. Main outcome measures were keratocyte density and maximum anterior stromal light reflectivity.
  
  
  RESULTS
  Mean epithelial healing time was 3.2 ± 0.4 and 3.0 ± 0.3 days in the mechanical and alcohol-assisted groups, respectively (P=.001). Anterior retroablation stromal keratocyte density was 704.3 ± 119.9 cells/mm² and 734.3 ± 103.7 cells/mm² at 3 months (P=.05) and 643.8 ± 134.4 cells/mm² and 696.7 ± 129.6 cells/mm² at 6 months (P=.02) in the mechanical and alcohol-assisted groups, respectively. No significant difference was noted in midstromal and posterior keratocyte density between the two groups. Maximum reflectivity was 61.56 ± 12.64 international units (IU) and 56.93 ± 7.86 IU in the mechanical and alcohol-assisted groups, respectively, 3 months after surgery (P=.018). Corresponding values were 49.46 ± 4.97 IU and 48.98 ± 4.60 IU, respectively, 6 months after surgery (P=.628).
  
  
  CONCLUSIONS
  Due to more adverse effects of mechanical epithelial debridement on anterior keratocyte density and anterior stromal reflectivity, alcohol-assisted epithelial debridement is recommended as the procedure of choice for epithelial removal during PRK in patients with mild myopia.
authors.affiliation: Ophtalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Bahram
authors.initials: B
authors.lastname: Einollahi
authors.forename: Alireza
authors.initials: A
authors.lastname: Baradaran-Rafii
authors.forename: Mozhgan
authors.initials: M
authors.lastname: Rezaei-Kanavi
authors.forename: Medi
authors.initials: M
authors.lastname: Eslani
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Parchegani
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zare
authors.forename: Sepehr
authors.initials: S
authors.lastname: Feizi
authors.forename: Farid
authors.initials: F
authors.lastname: Karimian
mesh_terms: D000328:Adult; D002452:Cell Count; D060527:Corneal Keratocytes / Q000473:pathology*; D003319:Corneal Stroma; D003646:Debridement / Q000379:methods*; D019573:Epithelium, Corneal / Q000187:drug effects / Q000503:physiopathology* / Q000601:surgery; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena; D018613:Microscopy, Confocal; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D014945:Wound Healing / Q000502:physiology*; D055815:Young Adult
chemical_list: D000431:Ethanol