RESUMEN
AIM:To evaluate the repeatability of axial length (AL) and anterior chamber depth (ACD) obtained by A scan ultrasonography, and to compare AL and ACD obtained by A scan with those obtained by IOL Master.METHODS:Two hundred and fifty-seven cataract eyes of 170 patients were included.IOL Master and A scan were performed for each eye.Five measurements of IOL Master and 3 measurements of A scan were obtained.All the tested eyes were divided into 5 groups according to AL obtained by A scan:Group A (2129mm, 21 eyes).Cronbach's Alpha coefficient and intraclass correlation coefficient (ICC) were applied to evaluate the repeatability of AL and ACD obtained by A scan.Paired t test and Pearson correlation coefficient were used to analyze the differences and correlations of AL and ACD obtained by the 2 devices, respectively.Bland-Altman plots were presented to analyze the agreements of AL and ACD obtained by the 2 devices.RESULTS:All the Cronbach's Alpha and ICCs of AL and ACD values were more than 0.98.The differences of AL values between A scan and IOL Master were-0.11±0.08mm in Group A,-0.15±0.10mm in Group B,-0.19±0.15 mm in Group C,-0.29±0.16mm in Group D and-0.45±0.29mm in Group E, respectively (all P0.89, all P<0.01).CONCLUSION:The AL and ACD values in cataract eyes obtained by A scan were repeatable.The AL and ACD values obtained by A scan were smaller than those obtained by IOL Master.With the increase of AL values, the differences of AL values between A scan and IOL Master increased.