Repeatability of central corneal thickness measurements of donor corneas in preservation chamber using Fourier-domain anterior segment optical coherence tomography.

Abstract

To evaluate the repeatability of central corneal thickness (CCT) measurements in donor corneas using optical coherence tomography (OCT, RTVue-Optovue, Inc., Fremont, CA). Consecutive corneas were measured by a single observer using the RTVue. All corneas were preserved in the Transend chamber and Life4°C media (Numedis, Inc., Isanti, MN/USA) and stored at 4°C. The repeatability was evaluated using a pooled within-subject standard deviation (SD), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). To investigate inter-observer repeatability, a second observer independently measured the CCT for each image scan. CCT was measured in 32 eyes from 18 donors. Measurements were independently repeated by a second observer. The corneas had a mean CCT of 490.99μm ± 65.95 (381-642) as measured by Observer 1. For observer 1, the SD value for the CCT was 2.94μm, the CoV value was 0.597%, and the ICC value was 0.998 (95% CI 0.996, 0.999). For observer 2, the SD value was 5.91μm, the CoV value was 1.21%, and the ICC value was 0.992 (95% CI 0.985, 0.996). The Kappa statistic 21.88% with a p value < 0.001. The Bland-Altman plot shows that the average CCT measurements between the two observers were within 20μm of each other. The CCT measurements of donor corneas in the preservation chamber using Fourier domain OCT is highly repeatable.