Agreement in corneal astigmatism measurements between Scheimpflug-Placido and swept-source optical coherence tomography-based optical biometers

To assess the agreement of anterior, posterior, and total corneal astigmatism measurements between IOLMaster 700 and Galilei G6 optical biometers. A single investigator performed both biometry measurements in a total of 62 eyes of 62 patients. Anterior, posterior, and total keratometry measurements were obtained, and flat (K1), steep (K2), astigmatic power, and J vectors (J0 and J45) were compared. To evaluate agreement and reliability between the devices, Bland-Altman plots and intraclass correlation coefficients (ICC) were calculated. There was a statistically significant difference in anterior K1, posterior K1, K2, J0, and total K1, J0 measurements (P < 0.05) between the IOLMaster and Galilei devices. Agreement analysis revealed significant proportional bias in anterior and posterior keratometry measurements and their vector components. Posterior corneal astigmatic components showed moderate reliability (ICC = 0.75–0.90) compared to anterior and total astigmatic components. Anterior, posterior, and total astigmatism are not interchangeable between the IOLMaster and Galilei G6 in both magnitude and axis. • Comparison of anterior, posterior, and total corneal astigmatism between IOLMaster 700 and Galilei G6 • Clinically significant differences observed, particularly in posterior and total corneal measurements • Findings highlight that astigmatism measurements from the two devices are not directly interchangeable for toric IOL planning