Comparison of axial length and anterior chamber depth measurements by IOLMaster, Axis- II A-scan and ODM 1000A sonograph

Background Axial length and anterior chamber depth are important parameters for the calculation of diopter of intraocular lens ( IOL ). Objective This study was to investigate and compare the measuring outcomes of axial length and anterior chamber depth with IOLMaster,Axis- Ⅱ A-scan and ODM 1000A sonograph.Methods This a observational study.Axial length and anterior chamber depth were measured in 83 eyes of 48 patients with IOLMaster,Axis-Ⅱ A-scan and ODM 1000A sonograph by the same operator.The measuring results were compared among the three methods.Results The axial length were(25.79±0.85) mm,(25.72± 0.82 )mm and ( 26.00 ±0.83 )mm respectively with Axis- Ⅱ,ODM 1000A sonograph and IOLMaster.The difference between Axis-Ⅱ and DM 1000A sonograph was (0.07 ± 0.35 )mm without statistical difference between them (t=1.711,P =0.091 ).The difference of axial length between IOLMaster and DM 1000A sonograph was ( 0.27 ±0.29) mm with a statistical difference between them ( t =-8.570,P =0.000 ).The difference between IOLMaster and Axis- Ⅱ was (0.21 ±0.32 ) mm and showed a statistical difference ( t =- 5.931,P ＜ 0.01 ).The positive correlations were found in the axial length values by the each other comparison among the three instruments( r=0.916,0.938,0.928,P＜0.01 ).The anterior chamber depth values were ( 3.81 ±0.21 ) mm,( 3.84 ±0.25 ) mm and ( 3.83 ±0.18 )mm respectively with Axis-Ⅱ,0DM 1000A sonograph and IOLMaster.The difference of anterior chamber depth between Axis- Ⅱ and DM 1000A was (0.03 ±0.17 ) mm without statistical difference between them ( t =- 1.324,P =0.189 ).The difference in the anterior chamber depth between IOLMaster and DM 1000A was (0.01 ±0.15 ) mm and that between IOLMaster and Axis-Ⅱ was( 0.01 ±0.12)mm without any statistical differences among them (t =0.815,P=0.417 ;t=-0.900,P=0.371 ).The high correlation between anterior chamber depth measurements were found by the each other comparison in the three instruments ( r =0.735,0.813,0.823,P ＜ 0.01 ).Conclusions ODM 1000A sonograph can provide precise axial length and anterior chamber depth values.However,ODM 1000Asonograph can not substitute for IOLMaster in the measurement of the anterior chamber depth and axial length.\r\n\r\nKey words: \r\nAxial length;  Anterior chamber;  A-scan;  IOLMaster;  sonography