title: Longitudinal postoperative lasik epithelial thickness profile changes in correlation with degree of myopia correction.
abstract: OBJECTIVE
  To evaluate epithelial thickness profile changes following myopic femtosecond laser-assisted LASIK in relation to the degree of myopia corrected, evaluated with a spectral-domain anterior-segment optical coherence tomography system.
  
  
  METHODS
  Sixty-one consecutive cases were observed for corneal epithelial thickness distribution preoperatively and at 1 day, 1 week, 1 month, and 1 year postoperatively. Epithelial thickness mapping was obtained with a spectral-domain optical coherence tomography system (Optovue Inc., Fremont, CA). Descriptive statistics investigated epithelial thickness at the central 2-mm area, the mean over the central 6-mm area, and mid-peripherally at the 5-mm ring area.
  
  
  RESULTS
  Preoperatively, the pupil center epithelial thickness was 51.67 ± 2.57 μm (range: 45 to 56 μm), mean was 51.76 ± 2.66 μm (range: 45 to 57 μm), and mid-periphery was 51.78 ± 2.71 μm (range: 46 to 57 μm). Compared to the preoperative values, the epithelial thickness for the center, mean, and mid-periphery was −0.30, +1.07, and +1.35 μm at 1 week, +1.58, +2.88, and +3.31 μm at 1 month (P = .0036, < .001, and < .001), and +1.42, +2.90, and +3.19 μm at 1 year postoperatively (P = 0.146, < .001, and < .001), respectively. The correlation analysis between the epithelial thickness increase and the spherical equivalent of myopic correction showed a trend toward epithelial thickness increase with the amount of myopic ablation, particularly at the mid-peripheral 5-mm area.
  
  
  CONCLUSIONS
  In this comprehensive study of postoperative corneal epithelial thickness remodeling following femtosecond laser-assisted myopic LASIK correction, an increase at the 1-month and up to 1-year postoperative interval suggested postoperative epithelial activity in connection to the extent of ablation.
authors.forename: Anastasios John
authors.initials: AJ
authors.lastname: Kanellopoulos
authors.forename: George
authors.initials: G
authors.lastname: Asimellis
mesh_terms: D000293:Adolescent; D000328:Adult; D063171:Corneal Pachymetry; D004847:Epithelial Cells / Q000473:pathology*; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D012029:Refraction, Ocular / Q000502:physiology; D041623:Tomography, Optical Coherence; D055815:Young Adult