Comparison of two swept-source optical biometers in eyes with long axial length

Purpose To assess the repeatability and agreement of two swept-source optical coherence tomography (SS-OCT)-based biometers when measuring biometric parameters in cataract eyes with a long axial length. Design Cross-sectional prospective, comparative study. Methods One-hundred and twenty-six eyes of 126 patients with cataracts (LOCS III grade equal or less than 3) and axial lengths >25 mm were measured 3 consecutive times using the Argos and IOLMaster 700 SS-OCT optical biometers. Keratometry [K1 (flat) and K2 (steep)], central corneal thickness (CCT), white-to-white (WTW), anterior-chamber-depth (ACD), lens-thickness (LT), and axial length were measured using both instruments. The repeatability for each device was analysed with the within-subject standard deviation (Sw), coefficient of variability, and coefficient of repeatability, and the agreement between the devices was analysed using a Bland–Altman plot. Results The acquisition success rate for both biometers was 100%. For K1 and K2, the Sw values were