Repeatability of whole-cornea measurements using a new swept-source optical coherence tomographer

Abstract

Purpose:

The aim of this study was to evaluate the repeatability of several corneal parameters provided by a high-resolution swept-source optical coherence tomographer (SS-OCT).

Methods:

One eye from each of 74 patients was measured five times consequently using the ANTERION SS-OCT. The following corneal parameters were analyzed: average, steep and flat keratometry (K), astigmatism for anterior, posterior and total at 3-mm, average K and astigmatism at 6-mm, anterior and posterior eccentricity, higher-order aberrations (HOA) and spherical aberration ( $Z_4^0$ ), and anterior and posterior best-fit sphere at 8-mm. The intrasubject standard deviation (S_w), coefficient of variation (CoV), coefficient of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated for each parameter to assess the repeatability.

Results:

We have not found statistically significant differences between repeated measurements (p > 0.05). Repeatability was good considering the different metrics used. S_w values were <0.09, varying from 0.035 (posterior average K at 6-mm) to 0.0878 (anterior flat K at 3-mm). CoV values were also low and similar among the different parameters (from 0.08% to 0.21%), except for anterior, posterior and total astigmatism (from 2.25% to 8.46%). Both anterior and posterior eccentricity, and corneal aberrations (HOA and $Z_4^0$ ) CoV values were also high. The CoR values were low for all parameters showing those related to the posterior cornea the lowest values (about 0.01). ICC values were >0.98.

Conclusions:

The ANTERION SS-OCT showed good repeatability when reconstructed different parameters for the whole cornea. This device produces measurements with high repeatability that could be useful for clinical research.