Central Vault and Anterior Chamber Angle Measurements After ICL Implantation: Repeatability and Reproducibility With a New Full-Range SS-OCT and Agreement With an Anterior Segment SS-OCT

Purpose: To assess the intraobserver repeatability and interobserver reproducibility of central vault and anterior chamber angle (ACA) measurements obtained with the YG-100K (TowardPi Medical Technology Ltd), a new full-range swept-source optical coherence tomography (SS-OCT) device, in eyes after Implantable Collamer Lens (ICL) implantation, and to evaluate their agreement with the established CASIA 2 anterior segment SS-OCT device (Tomey). Methods: This prospective study enrolled 78 myopic eyes (78 patients) after ICL implantation. Central vault, trabecular iris angle (TIA), angle opening distance, and trabecular iris space area were measured using the YG-100K and CASIA 2 devices. The automatic software of each device identified scleral spur and angle recess positions for ACA measurements. Repeatability and reproducibility were assessed using the within-subject standard deviation, test–retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Inter-device agreement was analyzed using paired t -tests and Bland-Altman plots. Results: The YG-100K demonstrated good to excellent repeatability and reproducibility for vault and ACA measurements, with CoVs ranging from 2.35% to 8.17% and ICCs between 0.888 and 0.997. The vault measured by the YG-100K was 15.38 ± 22.38 µm higher than the CASIA 2, with 95% limits of agreement (LoA) ranging from −28.48 to 59.24 µm. ACA measurements, except for TIA500, showed significant differences between devices, accompanied by wide 95% LoA ranges. Conclusions: The YG-100K provided reliable repeatability and reproducibility measurements in eyes after ICL implantation. Vault measurements showed good agreement with the CASIA 2, whereas discrepancies in ACA measurements indicated that these parameters should not be used interchangeably between devices.