Repeatability assessment of anterior segment biometric measurements in myopic patients using a new anterior segment OCT with Placido corneal topography and agreement with a swept-source OCT

Abstract

The precision of anterior segment biometric measurements in eyes has become increasingly important in refractive surgery. The purpose of this study is to assess the repeatability of the automatic measurements provided by a new spectral-domain optical coherence tomograph (SD-OCT)/Placido topographer (MS-39, CSO) and its agreement with a swept-source OCT (SS-OCT) biometer (CASIA SS-1000, Tomey) in patients with myopia. The right eye of 235 subjects was scanned 3 times with both devices. The evaluated parameters included central corneal radius of the steep meridian, central corneal radius of the flat meridian, mean central corneal radius, thinnest corneal thickness, central corneal thickness, anterior chamber depth, corneal volume and diameter. The repeatability of the MS-39 measurements was calculated using intraclass correlation coefficient (ICC), within subject standard deviation, coefficient of repeatability, coefficient of variation and repeated-measures analysis of variance. The agreement between the two devices was evaluated by 95% limits of agreement. The majority of the parameters showed high repeatability. The repeatability of corneal diameter was slightly lower than the other measurements, although the ICC remained high. Agreement with the SS-OCT was good for all parameters assessed. The high repeatability of automatic measurements by the new device supports its clinical application in myopic eyes with myopia, and the good agreement between the two devices indicates they could be used interchangeably for the parameters evaluated.