RESUMO
Background Biometry of the anterior ocular segment parameter is very important for the diagnosis and treatment of glaucoma and ocular injury as well as measurement of intraocular lens(IOL).Objective This study was to compare the differences in the anterior chamber depth(ACD) and the central corneal thickness (CCT) between Sirius and Pentacam and evaluate the agreement of these two measurement methods.Methods The ACD and the CCT of 38 right eyes from 38 health volunteers aged 23- 32 years were measured with both Pentacam and Sirius.Three times of measurement were pedormed on each eye for each method to obtain the average values.The repeatability and agreement from each method were assessed as intraclass correlation coefficient( ICC ) and coefficient of variation(CV) and the agreement between these two methods were evaluated using Bland-Altman mode.ResultsThe mean ACD value was( 3.18±0.21 ) mm from Pentacam with the ICC 0.995 and CV 0.066.The mean ACD value from Sirius was (3.22 ±0.21 )mm with the ICC 0.996 and CV 0.065.The difference value in ACD between two methods was 0.04 mm,showing a significant difference( t =-6.225,P＜0.05 ) and a positive correlation (r=0.977) between two methods.The 95％ limit of agreement was( -0.04-0.13)mm within 1 standard difference (SD) of the mean value( ±0.21mm),which was acceptable for clinical measurement.The CCT was( 535±33 )μm from Pentacam with the ICC 0.994 and CV 0.062.The CCT was(537±36)pm from Sirius with the ICC 0.999 and CV 0.067.The difference value in the CCT between two methods was about 2 μm,presenting a in significant difference ( t =1.771,P＞0.05 ) and positive correlation ( r =0.985 ).The 95 ％ limit of agreement was ( - 11.64-15.65 ) μm within 1 SD of the mean value( ±34.27 pm),which was acceptable for clinical measurement.ConclusionsSirius and Pentacam show good agreement in the measurement of ACD and CCT.The two methods offer an alternative choice for the biological measurement of the anterior ocular segment.