여러 가지 기기에서의 각막곡률 비교

Comparison of Corneal Curvatures Obtained with Different Devices

Purpose: To evaluate device efficacy using the corneal curvature value. Methods: 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. Results: 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. Conclusions: 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. J Korean Ophthalmol Soc 2012;53(5):618-625