title: Measurement of central corneal thickness with optical low-coherence reflectometry and ultrasound pachymetry in normal and post-femtosecond laser in situ keratomileusis eyes.
abstract: OBJECTIVE
  To determine the repeatability and reproducibility of measurements of central corneal thickness (CCT) using optical low-coherence reflectometry (Lenstar LS900; Haag Streit) in normal eyes and post-femtosecond laser in situ keratomileusis (post-FS-LASIK) eyes and evaluate their agreement with ultrasound (US) pachymetry.
  
  
  METHODS
  CCT was measured using Lenstar and US pachymetry sequentially in normal and post-FS-LASIK eyes by 2 experienced observers. Intraoperator repeatability and interoperator reproducibility were assessed by within-subject standard deviation, test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient. Paired t-tests and Bland-Altman plots were used for analyzing agreement between the 2 devices.
  
  
  RESULTS
  In this study, 55 healthy subjects and 50 post-FS-LASIK patients were recruited. Test-retest repeatability of Lenstar was within 10 μm, CoV was less than 1.0%, and intraclass correlation coefficient was more than 0.9 in both normal and post-FS-LASIK groups. Mean difference between these methods was 1.4 ± 4.2 μm and -1.7 ± 5.4 μm, respectively. Moreover, measurements of CCT showed narrow 95% limits of agreement (range, normal group: -6.8 and 9.6 μm; post-FS-LASIK group: -12.4 and 8.9 μm), which implied good agreement.
  
  
  CONCLUSIONS
  Measurements of CCT using Lenstar showed excellent intraoperator repeatability and interoperator reproducibility both in normal eyes and post-FS-LASIK eyes. Measurements of CCT using Lenstar and US pachymetry showed good agreement and both can be used interchangeably.
authors.affiliation: *Eye Hospital, Ophthalmology Institute, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China; †Key Laboratory of Vision Science, Ophthalmology Institute, Ministry of Health P.R. China, Wenzhou, China; and ‡G.B. Bietti Foundation IRCCS, Rome, Italy.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Huang
authors.forename: Na
authors.initials: N
authors.lastname: Liao
authors.forename: Giacomo
authors.initials: G
authors.lastname: Savini
authors.forename: Yuanguang
authors.initials: Y
authors.lastname: Li
authors.forename: Fangjun
authors.initials: F
authors.lastname: Bao
authors.forename: Ye
authors.initials: Y
authors.lastname: Yu
authors.forename: Ayong
authors.initials: A
authors.lastname: Yu
authors.forename: Qinmei
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D001699:Biometry / Q000379:methods*; D003315:Cornea / Q000033:anatomy & histology / Q000473:pathology*; D063171:Corneal Pachymetry / Q000379:methods*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery; D009887:Ophthalmoscopy; D009929:Organ Size; D011184:Postoperative Period; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult