Comparison of Horizontal White-to-white Diameter Measured Using Four Devices

Purpose: To compare the horizontal white-to-white (WTW) diameter measured using four devices.Methods: We measured the horizontal WTW diameter of 52 eyes of 52 patients using the IOL Master 500, ANTERION, OA-2000, and Pentacam HR devices. Repeated-measures analysis of variance was used to compare the measurements. Correlations between the measurements were evaluated using the Pearson correlation test. Agreement between measurements obtained using different instruments was confirmed using a Bland-Altman plot.Results: The mean horizontal WTW diameters obtained using IOL Master 500, ANTERION, OA-2000, and Pentacam HR were 11.65 ± 0.39, 11.52 ± 0.44, 11.51 ± 0.52, and 11.28 ± 0.41 mm, respectively. The horizontal WTW diameters obtained using IOL Master 500 and Pentacam HR were the largest and smallest, respectively. There was a statistically significant difference in mean diameter between IOL Master 500 and ANTERION (p = 0.03), as well as between Pentacam HR and the remaining three devices (all p < 0.001). There were positive correlations between the measurements obtained using the different devices (all r > 0.6, p < 0.001). The 95% limits of agreement between the measurements were 0.808-1.619 mm.Conclusions: There were statistically significant differences in horizontal WTW diameter between IOL Master 500 and ANTERION, and between IOL Master 500 and Pentacam HR, but not between IOL Master 500 and OA-2000. Measurements obtained using IOL Master 500 and the remaining three devices are not interchangeable because of their low level of agreement.