方法：选取2013-12/2014-12在我院眼科诊断为鼻泪管阻塞的知情同意的患者20 例20眼，经上泪小点打入玻璃酸钠直到下泪小点返流为止后，下泪小管行UBM检查，分别测量下泪小管相同部位闭眼及睁眼时的垂直部长度； 垂直部近心段、中段、远心段管腔的前后径； 水平部远心段、中段、近心段管腔的前后径和垂直径，根据椭圆面积公式S=πab(a，b分别为1/2前后径和1/2垂直径)计算出下泪小管水平部各段横截面积。闭眼、睁眼时相同部位泪小管垂直部长度、各段前后径间的比较以及水平部各段横截面积间的比较均采用配对t检验。

结果：闭眼、睁眼时下泪小管垂直部长度分别为：2.56±0.33、2.76±0.34mm，垂直部远心段前后径分别为：0.29±0.04、0.32±0.04mm，中段前后径分别为0.32±0.03、0.35±0.04mm，近心段前后径分别为0.38±0.02、0.40±0.04mm。闭眼、睁眼下泪小管垂直部长度、远心段、中段、近心段见管腔前后径的比较差异均有统计学差异(t=-5.346、-5.12、-4.94、-4.682，P<0.05)。下泪小管水平部闭眼、睁眼时管内横截面积：远心段分别：0.88±0.18、0.95±0.15mm²，中段分别：0.67±0.04、0.75±0.08mm²，近心段分别：0.51±0.10、0.56±0.15mm²。下泪小管水平部各段管内横截面积闭眼、睁眼间比较差异有统计学意义(t=-7.453、-6.73、-6.43，P<0.05)。

结论：和睁眼相比，闭眼时下泪小管垂直部长度变短，垂直部管腔前后径小及水平部管内径变小。

METHODS:Twenty volunteers(20 eyes)with nasolacrimal duct obstruction were included. The lower canaliculus of one eye in every volunteer was detected and measured with ultrasound biomicroscope when eyes opened and closed. Before measurements sodium hyaluronate was injected through the upper lacrimal puncta until it overflowed from the lower lacrimal puncta. The length of the vertical canaliculus, anteroposterior diameter of the vertical canaliculus at the proximal, middle, distal, anteroposterior diameter and vertical diameter of the horizontal canaliculus at the proximal, middle, distal were measured. According to elliptical area formula S=πab(a =1/2 anteroposterior diameter,b=1/2 vertical diameter), transverse area of the horizontal canaliculus at the distal, middle and proximal were calculated. The differences of measurement when eyes opened and closed were compared by paired t test.

RESULTS:When eyes opened and closed, the length of vertical canaliculus of inferior canaliculus were respectively 2.56±0.33 and 2.76±0.34mm; anteroposterior diameters at the distal part were respectively 0.29±0.04 and 0.32±0.04mm; those at the middle were respectively 0.32±0.03 and 0.35±0.04mm; those at the proximal were respectively 0.38±0.02 and 0.40±0.04mm and those differences between opened and closed eyes were statistically significant(t=-5.346, -5.12, -4.94, -4.682; P<0.05). When eyes opened and closed, the transverse ereas of horizontal part of lower canaliculus at the distal were respectively 0.88±0.18 and 0.95±0.15mm²; those at the middle were respectively 0.67±0.04 and 0.75±0.08mm²; those at the proximal were respectively 0.51±0.10 and 0.56±0.15mm² and those differences between opened and closed eyes were statistically significant(t=-7.453, -6.73, -6.43; P<0.05).

CONCLUSION:Compared with the opened eyes, the vertical length of lower canaliculus become shorter, the anteroposterior diameter of vertical canaliculus and transverse areas of horizontal canaliculus become smaller.