AIM: To compare the anterior segment measurements derived from optical low coherence reflectometer(Lenstar LS900)and combined Scheimpflug-Placido disk topographer(Sirius).

METHODS: In this study, we enrolled healthy myopic subjects 54(87 eyes). The central corneal thickness(CCT), anterior chamber depth(ACD), flat keratometry(FK)readings, steep keratometry(SK)readings and white to white(WTW)were measured by LS900 and Sirius. Evaluation and analysis were performed using paired t tests, the Pearson correlation, and Bland-Altman analyses.

RESULTS:The CCT and ACD measurements were significantly lower whereas FK, SK and WTW measurements were higher with LS900(P<0.001). Mean differences were -6.11±6.32μm,-0.09±0.07mm, 0.18±0.25D, 0.21±0.36D and 0.25±0.39mm with statistical significant(P<0.01). Pearson correlation analysis showed high correlation between the 2 devices for all measurements(P<0.001). On Bland-Altman analysis, 95% limits of agreement for all measurements were 6.26 to -18.49μm; 0.04 to 0.22mm; 0.68 to 0.32D; 0.92 to 0.50D and 1.00 to 0.5mm.

CONCLUSION: Anterior segment parameters evaluated with LS900 and Sirius systemare correlated well and achieve good agreement. However, there are significantly statistical differences which may be caused by the different measurement modes, so they may not be interchangeable use under certain clinical circumstances.