全景超声生物显微镜眼前段生物测量的准确性评价

Evaluation of accuracy of anterior segment biological measurement by panoramic ultrasound imaging UBM

目的对全景超声生物显微镜(UBM)测量中央角膜厚度(CCT)、前房深度(ACD)及房角开放度数(AA)的准确性进行评价。方法20例患者先行A型超声测量CCT和ACD,再分别用P40型UBM和全景UBM成像并测量CCT、ACD及12、3、6和9点方位AA。比较两种UBM所测量CCT和ACD与A型超声测量结果的一致性及在房角开放度数测量时的一致性。结果测量20例患者(39眼),A型超声测量组与全景UBM组组间ACD值差异无统计学意义(P=0.113),CCT值差异有统计学意义(P=0.001);P40型UBM测量组平均ACD与A型超声组间差异无统计学意义(P=0.811),CCT值较A型超声组小,差异有统计学意义(P=0.000)。P40型UBM与全景UBM所测量AA值除12点方位外,3、6、9点方位AA值差异均有统计学意义。结论全景UBM和P40型UBM在测量ACD时与A型超声结果均有良好的一致性;测量CCT时,两种UBM所测量均偏低,以P40型更明显。两种UBM所测量AA值仅12点方位具有良好的一致性。

Objective Ultrasound biomicroscope（UBM） is used to the study of anterior segment structures of human eye. It can measure central corneal thickness （CCT） , central anterior chamber depth （CACD） and anterior chamber angle, etc.. This study tried to evaluate the accuracy of panoramic UBM in the measurement of CCT, CACD, anterior chamber angle. Methods Twenty patients （39 eyes） who need UBM examination were enrolled in this study. CCT and ACD were measured by A-scan, Zeiss Humphrey P40 UBM and panoramic ultrasound imaging UBM respectively. The anterior chamber angle values at 12,3,6 and 9 clocks of eye were measured using these two types of UBM. Results The ACD value measured by A-scan was （2.36 ±0. 79） mm,and that measured by panoramic ultrasound imaging UBM and P40 UBM was （2. 28 ±0. 84）mm and （2.30 ±0. 85） mm respectively without statistically significant differences between ACD values by A-scan and UBM （P = 0. 113 ,P = 0. 811 ）. The CCT value measured by A-scan was （565.7 ± 36. 3） μm, showing a significant increasing thickness in comparison with that by panoramic ultrasound imaging UBM （528.8 ± 37.80） μm and P40 UBM （ 506.2±41. 0）μm （ P = 0. 001, P = 0. 000）. The mean values of anterior chamber angle measured by P40 UBM and panoramic ultrasound imaging UBM showed a statistically significant difference in 3,6,9 clock（t = -2. 517,P =0.009;t = - 2. 920,P =0. 022;t = -2. 689,P =0. 015）. Conclusion Panoramic ultrasound imaging UBM and P40 UBM have a good concordance in measurement of ACD with A-mode ultrasound,but the CCT value measured by UBM especially by P40 UBM is lower than that of A-mode ultrasound. The measurement outcome of anterior chamber angle value by these two types of UBM is only constant at 12 clock.