To evaluate device efficacy using the corneal curvature value.

Prospectively, 35 patients (70 eyes) were enrolled in the present study. Three sets of corneal curvature values were obtained using the autorefractor (RK-F1®), manual keratometer (OM-2®), partial coherence interferometry keratometer (IOL Master®), wavefront analyzer (KR-1W®), and videokeratography (Orbscan II®). Repeatability of each device was evaluated by coefficient of variation, standard deviation, and intraclass correlation coefficient. RM-ANOVA on ranks was used to compare the differences in corneal curvatures among the devices. The Bland-Altman plot was performed to assess measurement agreement among the devices.

The coefficient of variation values from each device ranged from 2.92% (IOL master®) to 3.06% (Orbscan II®), and the values of intraclass correlation coefficient ranged from 0.965 (KR-1W®) to 0.997 (IOL master®). Compared with the manual keratometer, there was a maximum corneal curvature difference of 1.23 D in KR-1W®, while the other devices had differences less than 0.82 D.

When assessing corneal curvature, the repeatability values were similar among the 5 devices, although a difference greater than 1 D was observed when comparing the KR-1W® to the manual keratometer.