AIM:To observe the accuracy of infiltrating B ultrasound guided A-scan segment biometric measurement of axial length in dense cataract.

METHODS: Perspective study. A total of 86 patients(90 eyes)with dense cataract were selected from Chengdu Aier Eye Hospital from August 2020 to August 2022. There were 61 males(59 eyes)males and 25 females(31 eyes)females, with an average age of 66.49±14.55 years. The axial length(AL), anterior chamber depth(ACD)(including corneal thickness), corneal curvature(K), lens thickness(LT), central corneal thickness(CCT), and white-to-white(WTW)were measured preoperatively by contact A-scan, infiltrating B ultrasound guided segmented A-scan, and IOL Master 700, respectively. At 1 wk postoperatively, AL was retested by IOL Master 700 in aphakic mode. Furthermore, the agreements and correlations of AL obtained by the three kinds of devices were analyzed.

RESULTS:The AL measured by contact A-scan and infiltrating B ultrasound guided segmented A-scan were 23.40(22.63, 23.89)mm and 23.70(23.04, 24.25)mm, respectively, and the AL measured by IOL Master 700 at 1 wk postoperatively was 23.72(23.01, 24.27)mm. There were statistical significant difference in AL measured by the three methods(P=0.018), while there were no statistical significant difference in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.991). Bland-Altman analysis showed that there was a good agreement in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.0809). The AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700 was positively correlated(r_s=0.992, P<0.0001), and the AL was positively correlated between preoperative contact A-scan and postoperative IOL Master 700(r_s=0.989, P<0.0001).

CONCLUSION:For dense cataract, infiltrating B ultrasound guided A-scan segment biometric measurement, which has good correlations and agreement, is closer to the AL measured by IOL Master 700 postoperatively than that measured by contact A-scan.