Comparison of central corneal thickness measured with anterior segment optical coherence tomography versus ultrasonic pachymetry

Abstract Purpose To compare central corneal thickness measured with anterior segment optical coherence tomography (AS-OCT) and ultrasonic pachymetry (UP). Method A prospective, observational and cross-sectional study was performed. The central corneal thickness was measured in 112 eyes of 112 consecutive patients with AS-OCT and UP. All examinations were performed by the same examiner. The measurements obtained between the two instruments were compared to assess the level of agreement. Results The average corneal thickness value obtained by AS-OCT was 531.47 ± 26.23 μm, while that measured by UP was 532.51 ± 26.04 μm. The intraclass correlation coefficient was 0.957 ( p t -test did not show a statistically significant difference (1.04 ± 7.70 μm, p  = .158). Finally, the Bland–Altman analysis showed a high level of agreement between two methods of measurement. Conclusions In the context of normal corneas, there was good agreement between the measurement of central corneal thickness with AS-OCT and UP, although there was a slight overestimation of the measurement using UP (1.04 μm).