Repeatability and Reproducibility of Anterior Segment Measurements with a New Full-Range SS-OCT and Comparison with an AS-OCT

To evaluate the intraobserver repeatability and interobserver reproducibility of anterior segment parameters measured by the new YG-100K full-range swept-source optical coherence tomographer (SS-OCT) and compare them with values from the validated CASIA 2 anterior segment optical coherence tomographer (AS-OCT). In a randomized sequence, the first operator conducted three consecutive measurements with both devices, while a second operator independently conducted three consecutive measurements with only the YG-100K. Each device's built-in software automatically identified the scleral spur and angle recess. Measured parameters included central corneal thickness (CCT), anterior chamber depth (ACD), angle-to angle (ATA) distance, anterior chamber width (ACW), lens vault (LV), crystalline lens rise (CLR), lens thickness (LT), trabecular iris angle (TIA), angle open distance (AOD) and trabecular iris space area (TISA). The within-subject standard deviation (Sw), test-retest (TRT) repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated. Bland-Altman plots were assessed inter-device agreement. The YG-100K demonstrated excellent repeatability and reproducibility, evidenced by low Sw, TRT, and CoV values, and ICCs nearing 1.000 (intraobserver ICCs: 0.918-0.998; interobserver ICCs: 0.972-0.998). Comparative analysis revealed good agreement for CCT and ACD. However, ATA and ACW were significantly lower, whereas LT, LV and CLR were slightly higher with YG-100K. Angle measurements between the two devices showed wide 95% limits of agreement (LoA). This new full-range SS-OCT exhibited high repeatability and reproducibility for anterior segment measurements, confirming its reliability. However, significant differences and wide 95% LoAs compared to the CASIA 2 suggested that these devices were not interchangeable.