Comparison of Keratometry Values Obtained by the Autorefractokeratometer, Galilei, and IOLMaster

Purpose: To assess the repeatability and comparability of keratometry values obtained by the autorefractokeratometer (RK-F1; Canon, Tokyo, Japan), Galilei dual Scheimpflug analyzer (Ziemer, Port, Switzerland), and the IOLMaster (Carl Zeiss Meditec, Jena, Germany). Methods: Keratometry values in the flat (Kf) and steep (Ks) axes were obtained by the autorefractokeratometer, Galilei, and the IOLMaster in 68 eyes from 68 healthy subjects. Each measurement was performed three times by a single examiner. The repeatability of three consecutive measurements was evaluated. Keratometry values were compared and the agreement among devices was assessed. Results: All devices showed high intraobserver repeatability for the keratometry measurements (intraclass correlation coefficient ≥ 0.992). The keratometry values obtained by the three devices were highly correlated with each other (Pearson correlation coefficient ≥ 0.957). The keratometry values measured by the IOLMaster (42.11 diopter [D] for Kf and 43.54 D for Ks) were greater than those from the autorefractokeratometer (41.99 D for Kf and 43.45 D for Ks) and Galilei (42.02 D for Kf and 43.42 D for Ks) (p-values ≤ 0.005). Conclusions: Repeatability of the values obtained with each device for keratometry measurements was good. Although the keratometry values obtained by the autorefractokeratometer and Galilei were not significantly different, the keratometry values of the IOLMaster were greater than other devices.