Comparison of a swept-source optical coherence tomograph device (MT9000) to a partial coherence interferometry-based biometer (IOLMaster 500) in a high-altitude environment.

To evaluate the agreement of biometry parameters of cataract patients between MT9000 (Vision Micro Image (Henan) Technology Co., Ltd.) and IOLMaster 500 (Carl Zeiss Meditec, Jena, Germany) in a high-altitude environment. A total of 145 eyes from the high-altitude region and 207 eyes from the low-altitude region had biometry measurements using MT9000 and IOLMaster 500. Axial length (AL), anterior chamber depth (ACD), white-to-white length (WTW), and keratometry (K1, K2, and Ke) values were obtained by both devices. Agreement was assessed based on intralclass correlation coefficient (ICC) and Bland–Altman analysis by calculating the mean difference and 95% limits of agreement (LoA). Propensity score matching analysis was used to control for age, sex, and AL among populations at different altitudes. The ICC values and the LOA ranges measured by the two devices for AL, ACD, WTW, and K(K1, K2, and Ke) were 0.996, 0.799, 0.660, 0.976, 0.967, 0.978, and 0.055 to 0.148 mm, -0.499 to 0.217 mm, -0.443 to 0.552mm, -0.636 to 0.615mm, -0.785 to 0.793mm, -0.595 to 0.609mm, respectively. The differences among different cataract grade groups and different altitude groups were not statistically significant (P > 0.05). MT9000 and IOLMaster 500 showed excellent agreement in measuring AL and K(K1, K2, and Ke), good agreement in measuring ACD, and moderate agreement in measuring WTW in cataract patients in high-altitude environments. Although there were statistically significant differences, the magnitudes were below clinically significant thresholds. In situations requiring precise ACD and WTW measurement, MT9000 cannot replace IOLMaster 500.