Intraobserver Repeatability of Tomographic, Pachymetric, and Anatomical Measurements in Healthy Eyes Using a New Swept-Source Optical Coherence Topographer

Abstract

Purpose: The purpose of this study was to evaluate the intraobserver repeatability of several corneal parameters in healthy eyes using a new swept-source optical coherence topographer.

Methods: Fifty right eyes of 50 subjects were enrolled in this study. A single examiner performed 3 consecutive measurements using the Anterion swept-source optical coherence tomography. The following corneal parameters were evaluated: average keratometry (K), steep K, flat K, astigmatism, best fit sphere, and maximum keratometry on the anterior and posterior surfaces at 3 mm, average K, steep K, flat K, and astigmatism in the total corneal power map at 3 mm, central corneal thickness and thinnest point thickness in the pachymetric map, and corneal diameter. To assess the repeatability of the measurements, we calculated the following indexes: intrasubject SD (Sw), coefficient of variation, coefficient of repeatability, and intraclass correlation coefficient (ICC).

Results: High repeatability was reported for all the evaluated corneal parameters, with Sw values lower than 0.027, coefficient of variation values lower than 0.066%, and coefficient of repeatability values lower than 0.187. ICC values showed a high correlation between measurements in all cases, being the lowest value for the astigmatism of the anterior surface (ICC = 0.92); for the rest, ICC values were larger than 0.98. Finally, we have not found statistically significant differences between repeated measurements (P > 0.05).

Conclusions: The anterior segment measurements provided by the Anterion swept-source optical coherence tomography device show high intraobserver repeatability in healthy eyes.