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

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).

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 ($$), 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.

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 $$) 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.

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.