Agreement and repeatability of corneal tomography in healthy eyes using a new swept-source OCT, a rotating Scheimpflug camera, and a dual Scheimpflug-Placido system.

Abstract

To investigate the accordance and repeatability of tomographic parameters measured by a new swept-source optical coherence tomographer (SS-OCT, ANTERION), a rotating Scheimpflug camera (RSC, Pentacam), and a dual Scheimpflug-Placido system (DSP, Galilei G6). Department of Ophthalmology of University of Hospital Carl Gustav Carus, Dresden, Germany. Prospective reliability analysis. Normal tomography was ensured by bilaterally evaluating appropriated parameters using RSC. All subjects received 3 consecutive measurements on each device by the same operator and in the uniform order RSC, SS-OCT, and DSP. Anterior (ACP) and posterior (PCP) corneal parameters such as flat and steep keratometry and corneal thickness were analyzed. Repeatability was assessed by using a coefficient of repeatability (CoR) and a coefficient of variation. Agreement between RSC and SS-OCT and between RSC and DSP were shown by Bland-Altman plots. This study included 30 randomly selected eyes of 30 healthy participants. CoR of ACP did not exceed 0.5 diopters. There were no statistically significant differences in repeatability of ACP obtained from the 3 devices (P > .05). For PCP and corneal thickness, there was statistically significant higher repeatability mostly found for SS-OCT as opposed to RSC and DSP (P < .05). For a wide range of analyzed parameters, there were large limits of agreement (95% LoA) found between the devices. The SS-OCT showed highly repeatable measurements in healthy subjects regarding anterior, posterior, and corneal thickness parameters. Repeatability of ACP did not differ between the devices. A mostly wide range of 95% LoA prevents interchangeability between the devices.