Ultrosound Imaging Of Lacrimal Passage And Its Physiological Measurement

Objective To evaluate the ultrasound imaging and physiological measurement of lacrimal passage in normal subjects and to provide the basis for diagnosis of its diseases with ultrasound.Methods Lacrimal passages in 235 normal adults were examined by utrasonography. The volunteers were placed in the supine position and closed their eyes. Their orbitals were filled fully by ultrasonic coupling jelly to reduce the gap between the orbit and the ultrasonic probe. The bilateral lacrimal sacs were examined respectively in the transverse scaning. The transverse diameter between walls was measured when the lacrimal sac was showed the largest transverse section. The longitudinal section of lacrimal sac was obtained as rotating the ultrasonic probe. And then the length and anteroposterior diameter were measured. At the same time, the thickness of lacrimal sac wall was measured. When rotating slightly the probe, the lacrimal canaliculus was found. And its internal diameter was measured. Based on the imaging of lacrimal passages, the detection rate, ultrasonic appearance and physicological measurement were analyzed. Quantitative dates were compared between groups.Results (1) The detection rate of lacrimal sac was highest. The detection rate of the naso-lacrimal duct was relatively lower than that of the lacrimal canaculus. The detection rate of the lacrimal sac, lacrimal canaliculus and naso-lacrimal duct was 91.9%～93.6%,14.9%～14.9% and 0%～0.4%, respectively. (2) The length of the left lacrimal sac was longer than that of right side in the group of the same sex (P<0.01). The length and anteroposterior diameter of the lacrimal sac in male group were longer than those in female group (P<0.05, P<0.01, respectively). (3) On ultrasonography, the lacrimal passage appeared as a hypoechoic or anechoic region. The shape of the lacrimal passage was tublar, round or elliptical.Conclusions The lacrimal sac can be clearly showed on ultrasongraphy. Because the lacrimal canaliculus are thin, narrow and strongly scalable, the detection rates are relatively low. And the naso-lacrimal ducts are hardly detected because of the bone structure. Ultrasound imaging and physiological measuremet of lacrimal passage may have potential application in clinical practice.