title: Anterior Chamber Angle and Anterior Chamber Volume in a 40- to 64-Year-Old Population.
abstract: OBJECTIVE
  To determine the distribution of the anterior chamber angle (ACA) and anterior chamber volume (ACV) in an Iranian population of 40- to 64-year-old people using the Pentacam.
  
  
  METHODS
  In this cross-sectional study, multistage sampling was used to select 300 clusters, including 6,311 individuals from the city of Shahroud. All selected participants underwent examinations in one place. Optometric examinations, including measurement of visual acuity and refraction, and ophthalmologic examinations, including slit-lamp examination, were performed for all participants. Moreover, all patients underwent imaging with the Pentacam.
  
  
  RESULTS
  The mean ACA and ACV was 34.3° (95% confidence interval [CI]: 34.1°-34.5°) and 139 μL (95% CI: 137.7-140.3), respectively. In a multiple linear regression model, the ACA was inversely correlated with age (coefficient=-0.08), lens thickness (coefficient=-1.38), corneal diameter (coefficient=-0.36), and corneal curvature (coefficient=-1.43), and directly correlated with the anterior chamber depth (ACD) (coefficient=6.59). In another model, ACV was inversely correlated with age (coefficient=-0.37), central corneal thickness (coefficient=-0.04), and spherical equivalent (coefficient=-1.15), and directly correlated with the ACD (coefficient=85.67), lens thickness (coefficient=14.15), corneal diameter (coefficient=4.80), corneal curvature (coefficient=18.43), ACA (coefficient=0.65), and intraocular pressure (coefficient=0.23).
  
  
  CONCLUSIONS
  The findings of this study could be used as a reference for diagnosis and treatment in Iran and the Middle East region. Increase in age and decrease in the ACD were important factors associated with decreased ACA and ACV, although the correlation of other biometric components was also evaluated. Some of these components, such as the corneal curvature and lens thickness, had a significant relationship with these two variables.
authors.affiliation: Noor Ophthalmology Research Center (H.H., M.K., S.M.-T., N.D.), Noor Eye Hospital, Tehran, Iran; Center for Health Related Social and Behavioral Sciences Research (M.H.E.), Shahroud University of Medical Sciences, Shahroud, Iran; Department of Community Medicine, School of Medicine (M.S.), Tehran University of Medical Sciences, Tehran, Iran; and Department of Epidemiology and Biostatistics (A.F.), School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Hashemi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Khabazkhoob
authors.forename: Saman
authors.initials: S
authors.lastname: Mohazzab-Torabi
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Emamian
authors.forename: Mohammad
authors.initials: M
authors.lastname: Shariati
authors.forename: Nooshin
authors.initials: N
authors.lastname: Dadbin
authors.forename: Akbar
authors.initials: A
authors.lastname: Fotouhi
mesh_terms: D000328:Adult; D000367:Age Factors; D000867:Anterior Chamber / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D001699:Biometry / Q000295:instrumentation* / Q000379:methods*; D001794:Blood Pressure; D015992:Body Mass Index; D019781:Corneal Topography / Q000295:instrumentation* / Q000379:methods*; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000000981:diagnostic imaging* / Q000208:ethnology*; D006068:Gonioscopy / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007429:Intraocular Pressure; D007492:Iran; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012737:Sex Factors; D012907:Smoking; D014792:Visual Acuity