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

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.

Observational cross-sectional study.

Fifty eyes from 50 healthy subjects were recruited.

CCT, CACD, and ACV were measured. Subjects were re-examined twice within a week of the first measurements. Intrasession and intersession within-subject SD (Sw), precision (1.96 × Sw), coefficient of variation (CVw: 100 × Sw / 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.

For intrasession repeatability, CVw and 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, CVw 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).

Although the Pentacam measurements of the anterior segment parameters were reliable, their agreement with the AS-OCT measurements was not sufficient.