Comparative study of anterior segment measurement with Pentacam and anterior segment optical coherence tomography

Objective: To evaluate the repeatability of central corneal thickness (CCT), anterior chamber volume (ACV), and central anterior chamber depth (CACD) measurements obtained using a Pentacam rotating Scheimpflug camera, and to examine their agreement with measurements obtained using an anterior segment optical coherence tomography (AS-OCT) imaging system.Design: Observational cross-sectional study.Participants: Fifty eyes from 50 healthy subjects were recruited.Methods: CCT, CACD, and ACV were measured. Subjects were re-examined twice within a week of the first measurements. Intrasession and intersession within-subject SD (S_w), precision (1.96 × S_w), coefficient of variation (CV_w: 100 × S_w/ overall mean), and intraclass correlation coefficient (ICC) were calculated to evaluate repeatability and reproducibility. Bland-Altman plots were used to assess agreements between Pentacam and AS-OCT measurements.Results: For intrasession repeatability, CVwand ICC values were 0.78 and 0.98 for CCT, 0.92 and 0.99 for CACD, and 3.52 and 0.98 for ACV, respectively. For intersession repeatability, CV_w and ICC values were 1.19 and 0.96 for CCT, 1.25 and 0.99 for CACD, and 3.96 and 0.96 for ACV, respectively. The AS-OCT CCT measurement (519.23 [SD 34.37] μm) was 18.53 μm less than the Pentacam measurement (537.76 [SD 31.84] μm). The Pentacam CACD measurement (3.03 [SD 0.32] mm) was 0.08 less than the AS-OCT measurement (3.11 [SD 0.31] mm). The Pentacam ACV measurement (165.56 [SD 34.86] μL) was 14.21 μL less than the AS-OCT measurement (179.77 [SD 34.57] μL).Conclusions: Although the Pentacam measurements of the anterior segment parameters were reliable, their agreement with the AS-OCT measurements was not sufficient.