title: Anterior chamber depth in elderly Chinese: the Liwan eye study.
abstract: OBJECTIVE
  To assess the anterior chamber depth (ACD) and its variation with age, gender, and angle width in elderly Chinese in an urban area of southern China.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Adults 50 and older were identified using cluster random sampling in Liwan District, Guangzhou.
  
  
  METHODS
  Gonioscopy was performed before ACD measurements to estimate the geometric angle width according to the Shaffer system. ACD was measured using optical pachymetry. True ACD was calculated by subtracting central corneal thickness from the distance between the anterior corneal epithelium and the anterior lens capsule. Data were presented for the right phakic eyes.
  
  
  METHODS
  Anterior chamber depth and gonioscopy.
  
  
  RESULTS
  Among 1405 participants in the study, data from 1248 right eyes were available for analysis. The mean ACD values for men and women were 2.59 mm (95% confidence interval [CI], 2.56-2.62; 25th-75th percentile, 2.37-2.82) and 2.42 mm (95% CI, 2.39-2.44; 25th-75th percentile, 2.21-2.63). Mean ACD declined by 0.09 mm (95% CI, -0.011 to -0.008) per decade (adjusted for gender) and was 0.18 mm (95% CI, -0.213 to -0.141) shallower in women than men (adjusted for age). The ACD was found to be monotonically associated with gonioscopic angle width, decreasing from 2.73 mm (standard deviation [SD], 0.26) in Shaffer grade 4 to 1.94 mm (SD, 0.27) in Shaffer grade 0. There was also a relationship between ACD and refractive error; mean spherical equivalent decreased by 0.030 mm ACD per diopter.
  
  
  CONCLUSIONS
  This study confirms an inverse association between ACD and age, female gender, and spherical refractive error. Eyes with shallower ACDs had narrower angles.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China. mingguang_he@yahoo.com
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
authors.forename: Wenyong
authors.initials: W
authors.lastname: Huang
authors.forename: Yingfeng
authors.initials: Y
authors.lastname: Zheng
authors.forename: Poul Helge
authors.initials: PH
authors.lastname: Alsbirk
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000867:Anterior Chamber / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D044466:Asian People / Q000208:ethnology; D001837:Body Weights and Measures; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000208:ethnology; D006068:Gonioscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D014463:Ultrasonography; D014505:Urban Population / Q000706:statistics & numerical data