title: Flap thickness reproducibility in laser in situ keratomileusis with a femtosecond laser: optical coherence tomography measurement.
abstract: OBJECTIVE
  To compare ultrasound (US) pachymetry, Orbscan, and optical coherence tomography (OCT) measurements of the central corneal thickness (CCT) before laser in situ keratomileusis (LASIK) and evaluate the reproducibility of flaps created with the IntraLase femtosecond laser (IntraLase, Inc.) using OCT.
  
  
  METHODS
  Department of Ophthalmology, IIsan Paik Hospital, Goyang, Korea.
  
  
  METHODS
  Central corneal thickness was measured using OCT, US pachymetry, and Orbscan in 59 eyes of 30 patients before femtosecond laser LASIK. The postoperative corneal flap thickness, measured using OCT, was compared with the preoperative intended thickness.
  
  
  RESULTS
  Optical coherence tomography, US pachymetry, and Orbscan measurements provided similar CCT values (P>.05). Corneal thickness values obtained using US or Orbscan correlated well with those obtained by OCT, with the correlation coefficient ranging from 0.804 to 0.889 (P<.05). The OCT measurements showed no significant difference between the postoperative flap thickness and the intended flap thickness (P>.05).
  
  
  CONCLUSIONS
  Optical coherence tomography was comparable to US pachymetry and Orbscan in cornea thickness measurement. Optical coherence tomography was easy and relatively accurate to use preoperatively and in the early postoperative period. The femtosecond laser created highly reproducible flaps that corresponded with the preoperative intended thickness.
authors.affiliation: Department of Ophthalmology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang-si, Korea. jhk0924@hanmail.com
authors.forename: Jin-Hyoung
authors.initials: JH
authors.lastname: Kim
authors.forename: Doh
authors.initials: D
authors.lastname: Lee
authors.forename: Kang-Il
authors.initials: KI
authors.lastname: Rhee
mesh_terms: D000328:Adult; D001837:Body Weights and Measures; D003315:Cornea / Q000473:pathology; D003319:Corneal Stroma / Q000473:pathology*; D019781:Corneal Topography / Q000379:methods; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods; D011300:Preoperative Care; D011446:Prospective Studies; D015203:Reproducibility of Results; D013524:Surgical Flaps / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*