Is it possible to replace automated keratometry with current devices: Comparison with lenstar and OPD II

Purpose: To compare the keratometry results obtained with optical low-oherence reflectometer, corneal topography, and automated keratometry readings and to assess the interexaminer reproducibility of each device. Ma te ri al and Met hod: This comparative study examined 65 eyes of 65 healthy subjects. Detailed ophthalmic examination was performed in all cases following keratometry measurements with a KR 8100A (Topcon, Japan), an OPD Scan II (Nidek, Japan), and a LenStar LS900 (Haag-Streit, Switzerland). Patients with spheric values over ±3.0D or cylindric values over ±1.0D and with history of chronic ocular/systemic disease or contact lens usage were excluded from the study. The keratometry readings were compared by using ANOVA test (SPSS 16.0). A p-value lower than 0.05 was taken as statistically significant. Bland-Altmann analysis was used to demonstrate agreement between methods, and Spearman rank correlation coefficient (r) was calculated for the correlation. To assess the interexaminer reproducibility, intraclass correlation coefficient was calculated in 30 eyes for each device. Re sults: The mean age of the 65 patients enrolled in the study was 21.9±3.25 years. The mean keratometric values obtained with the autorefractokeratometer, OPD Scan II, and LenStar LS 900 were 43.30±1.47, 43.42±1.44, and 43.29±1.42 respectively. No statistically significant difference was observed among the three groups (p=0.840). Interexaminer intraclass correlation was found as 78.9%, 99.9%, and 99.7% for ARK, OPD, and LenStar, respectively. Dis cus si on: LenStar has provided comparable and well-correlated keratometry measurements in comparison with automated keratometer and corneal topography.