Comparative Study Between AL-scan And Ultrasonic A-mode Scan In Measuring Ocular Biometry Parameter And Intraocular Lens Power

ObjectiveTo compare the difference of ocular biometry parameter and intraocular lens power measured by AL-scan and A-scan,to evaluate the clinical value of AL-scan.MethodsMeasurements of axial length(AL),anterior chamber depth(ACD)and average keratometry(K)by AL-scan and A-scan on the cataract patients 75 patients(110 eyes),they were divided into three groups according to AL,group A:22 mm ?AL<24.5 mm 46 patients(66 eyes),group B:24.5 mm ?AL<26 mm 14 patients(21 eyes),group C:AL?26 mm 15 patients(23 eyes),IOL power was calculated using the SRK-T formula.The case was followed in postoperative one month.ResultsThere was statistical difference in AL,ACD in group A and C(P < 0.05)AL between A-scan and AL-scan,there was no statistical difference in group B(P >0.05);there was no statistical difference in K value in three groups(P>0.05);The MAE with AL-scan in three groups was(0.32±0.22)?(0.48±0.55)?(0.56±0.46)D,with A-scan was(0.34±0.23)?(0.15±0.09)?(0.50±0.38)D,there was no statistical difference in MAE in three groups(P > 0.05).they also showed the excellent relation.ConclusionsThe AL and ACD values measured by AL-scan are longer than A-scan in three groups,there was no significant difference in measuring IOL power,AL-scan could be used in measuring IOL power.