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.
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.
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.
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.
*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.
Reprints: Qinmei Wang, MD, Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou 325027, Zhejiang, China (e-mail: firstname.lastname@example.org).
Supported in part by the Natural Science Foundation of China (81300807); Foundation of Wenzhou City Science & Technology Bureau (Y20130118, Y20120176); the National Science and Technology Ministry (2012BAI08B04); the health Bureau of Zhejiang Province (2012KYB135); and the Scientific Research Fund of Zhejiang Provincial Education Department (Y201223147).
The authors have no funding or conflicts of interest to disclose.
Received August 14, 2014
Received in revised form October 16, 2014
Accepted October 29, 2014