Intrasession repeatability of pachymetry measurements with RTVue XR 100 optical coherence tomography in normal cornea

Abstract

PurposeTo assess intra-observer reproducibility and repeatability of corneal pachymetry measurements with RTVue XR-100 anterior segment optical coherence tomography (AS-OCT) in normal cornea. MethodsEighty-four eyes of 84 healthy volunteers were enrolled for this study. A single examiner performed 3 successive corneal pachymetry mappings with RTVue XR-100 AS -OCT in a single session. One eye was randomly selected for the analysis. Intrasession intraexaminer reproducibility and repeatability were calculated for the minimum corneal thickness (MCT), central corneal thickness (CCT, central 0–2mm), pericentral (2–5mm) and peripheral (5–6mm) annular zones of cornea, in the pachymetry mapping protocol by intraclass correlation coefficient (ICC), coefficient of variation and test retest variability. ResultsThe mean CCT was 497.08±32.83µm and MCT was 490.28±32.87µm. ICC was 0.994 for CCT and 0.983 for MCT in central 2mm zone. ICC in the pericentral 2–5mm zones and 5–6mm zone was lower than that in central 2mm zone, but were still over 0.961 in 2–5mm zone and had ICC of 0.85 in 5–6mm zone. ConclusionIn normal cornea, corneal thickness measurements produced highly repeatable pachymetry measurements at the central and paracentral zones (up to 6-mm diameter) which could be because of the high resolution and faster image acquisition with RTVue XR-100 OCT.