title: [Measurement of canaliculus with ultrasound biomicroscopy].
abstract: OBJECTIVE
  To study biometric measurements of normal canaliculus in vivo with ultrasound biomicroscope.
  
  
  METHODS
  Cross-sectional study. Eighty volunteers of normal lacrimal duct (80 eyes), including 40 men (40 eyes), 40 women (40 eyes), aged from 18 to 82 years old (average 41 years old). Eighty volunteers were divided into three stages, one eye of each volunteer was detected and measured with ultrasound biomicroscope in the goggle state and the imaging characteristics of canalicular ultrasound biomicroscopy were obtained. The length of the vertical canaliculus, the distal, middle, proximal anteroposterior diameter of the vertical canaliculus, the distal, middle, proximal anteroposterior diameter and vertical diameter of the horizontal canaliculus were measured. According to elliptical area formula S = πab (a = 1/2 anteroposterior diameter, b = 1/2 vertical diameter)the distal, middle, proximal transverse erea of the horizontal canaliculus were caculated. The differences among age groups and those among distal, middle, proximal measurements were compared by One-way ANOVA analysis. The measurements of canaliculus between male and female were analyzed using t test.
  
  
  RESULTS
  Eighty volunteers (80 eyes) participated in the study, 6 eyes were failed to be imaged, the success rate was 92.5% (74/80). The length of vertical canaliculus of superior canaliculus were (2.10 ± 0.12) mm, of inferior canaliculus were (2.08 ± 0.10) mm. The proximal, middle, distal anteroposterior diameter of the vertical part of superior canaliculus respectively were (0.24 ± 0.05) mm, (0.28 ± 0.05) mm, (0.33 ± 0.04) mm (F = 16.315, P = 0.000), of inferior canaliculus were (0.23 ± 0.04) mm, (0.28 ± 0.06) mm, (0.32 ± 0.05) mm (F = 17.570, P = 0.000). The proximal, middle, distal transverse erea of the horizontal part of superior canaliculus respect were (0.77 ± 0.13) mm(2), (0.62 ± 0.13) mm(2), (0.48 ± 0.11) mm(2) (F = 22.970, P = 0.000), of inferior canaliculus were (0.79 ± 0.11) mm(2), (0.63 ± 0.08) mm(2), (0.48 ± 0.09) mm(2) (F = 21.45, P = 0.000). There was no significant difference of the canaliculus measurements between male and female (t = 0.105 - 0.487, P > 0.05). No significant differences were found among age groups (F = 0.142 - 3.954, P > 0.05).
  
  
  CONCLUSIONS
  It is practicable to measure the normal canaliculus in vivo with UBM.
authors.affiliation: Department of Ophthalmology, Armed Police General Hospital, Beijing, China.
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Xu
authors.forename: Hai
authors.initials: H
authors.lastname: Tao
authors.forename: Cui
authors.initials: C
authors.lastname: Han
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000000981:diagnostic imaging*; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D055815:Young Adult