title: Comparison of factors associated with occludable angle between american Caucasians and ethnic Chinese.
abstract: OBJECTIVE
  To determine if factors associated with gonioscopy-determined occludable angle among American Caucasians are similar to those found in ethnic Chinese.
  
  
  METHODS
  This is a prospective cross-sectional study with 120 American Caucasian, 116 American Chinese, and 116 mainland Chinese subjects. All three groups were matched for sex and age (40-80 years). Gonioscopy was performed for each subject (occludable angles = posterior trabecular meshwork not visible for ≥2 quadrants). Anterior segment optical coherence tomography and customized software was used to measure anterior segment biometry and iris parameters, including anterior chamber depth/width (ACD, ACW), lens vault (LV), and iris thickness/area/curvature.
  
  
  RESULTS
  In both Chinese and Caucasians, eyes with occludable angles had smaller ACD and ACW, and larger LV and iris curvature than eyes with open angles (all P < 0.005). Chinese eyes had smaller ACD and ACW than Caucasian eyes (both P < 0.01) in the occludable angle cohort. Iris characteristics did not differ significantly between Chinese and Caucasians in the occludable angle cohort. Based on multivariate logistic regression, gonioscopy-determined occludable angle was significantly associated with LV, iris area, and sex (all P < 0.03) in Chinese; and with LV, ACD, iris thickness, age, and sex (all P < 0.04) in Caucasians.
  
  
  CONCLUSIONS
  Several factors associated with occludable angle differed between Caucasians and Chinese, suggesting potentially different mechanisms in occludable angle development in the two racial groups. This is the first study to demonstrate that lens vault is an important anterior segment optical coherence tomography parameter in the screening for angle closure in Caucasians. In addition, iris thickness was a significant predictor for occludable angles in Caucasians but was not in ethnic Chinese.
authors.affiliation: University of California, San Francisco, California.
authors.forename: Ye Elaine
authors.initials: YE
authors.lastname: Wang
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Li
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
authors.forename: Shan
authors.initials: S
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000473:pathology / Q000503:physiopathology; D001213:Asian; D003430:Cross-Sectional Studies; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000208:ethnology* / Q000503:physiopathology; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D041623:Tomography, Optical Coherence / Q000379:methods*; D014129:Trabecular Meshwork / Q000503:physiopathology*; D014481:United States / Q000453:epidemiology; D044465:White People
keywords: ASOCT; angle closure glaucoma; gonioscopy; multiethnicity; occludable angle