title: Comparisons of anterior segment biometry between Chinese and Caucasians using anterior segment optical coherence tomography.
abstract: OBJECTIVE
  To compare anterior segment parameters between eyes of Chinese and Caucasians using anterior segment optical coherence tomography and to evaluate the association between these parameters and anterior chamber angle width between the two ethnic groups.
  
  
  METHODS
  60 Chinese and 60 Caucasians, 30 with open angles and 30 with narrow angles (defined as Shaffer grade < or =2 in > or =3 quadrants during dark room gonioscopy) in each group, were consecutively enrolled. One eye of each subject was randomly selected for imaging in a completely darkened room. Measurements, including anterior chamber depth (ACD), scleral spur-to-scleral spur distance (anterior chamber width (ACW)), anterior chamber angle width, iris convexity and iris thickness, were compared between the groups. The associations between angle opening distance and biometric measurements were evaluated with univariate and multivariate regression analyses.
  
  
  RESULTS
  There were no differences in age, axial length, anterior chamber angle measurements, pupil diameter and iris convexity between Chinese and Caucasians in both open-angle and narrow-angle groups. However, the ACD and ACW were smaller and the iris was thicker in Chinese. In the multivariate analysis, the ACD was the most influential biometric parameter for angle opening distance in both Chinese and Caucasians. After adjusting the effects of axial length, age and sex, ACD and ACW were significantly smaller in Chinese.
  
  
  CONCLUSIONS
  Chinese eyes had smaller ACD, smaller ACW and greater iris thickness than Caucasians. ACD was the most influential parameter in determining the angle width in both ethnic groups.
authors.affiliation: Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong, PR China. tlims00@hotmail.com
authors.forename: C K
authors.initials: CK
authors.lastname: Leung
authors.forename: P-M
authors.initials: PM
authors.lastname: Palmiero
authors.forename: R N
authors.initials: RN
authors.lastname: Weinreb
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Sbeity
authors.forename: S
authors.initials: S
authors.lastname: Dorairaj
authors.forename: D
authors.initials: D
authors.lastname: Leung
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: J M
authors.initials: JM
authors.lastname: Liebmann
authors.forename: N
authors.initials: N
authors.lastname: Congdon
authors.forename: D S
authors.initials: DS
authors.lastname: Lam
authors.forename: R
authors.initials: R
authors.lastname: Ritch
mesh_terms: D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D044466:Asian People; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000208:ethnology / Q000473:pathology; D006068:Gonioscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D041623:Tomography, Optical Coherence; D044465:White People