title: Anterior chamber angle biometry: quadrant variation, age change and sex difference.
abstract: OBJECTIVE
  To estimate the anterior change angle width (ACAW) in healthy volunteers quantitatively using an anterior eye segment analysis system and to clarify the involvement of aging and sex in ACAW.
  
  
  METHODS
  The ACAW of the upper, lower, medial, and lateral quadrants of 42 eyes from 42 healthy volunteers was measured by the NIDEK EAS-1000 anterior eye segment analysis system, a non-invasive in vivo measuring method based on Scheimpflug image analysis. Data from all subjects were employed to investigate aging and quadrant differences; and age-matched male and female subjects were chosen from all subjects to study sex difference and aging.
  
  
  RESULTS
  Young subjects showed no significant inter-quadrant differences of ACAW. However, ACAW showed a significant negative correlation with age in all quadrants, but the lateral quadrant showed much more narrowing than the others. The age-matched study revealed that ACAW narrowing was much greater in females than in males, and a polynomial regression analysis showed that this sex difference appeared in subjects older than middle age.
  
  
  CONCLUSIONS
  The anterior eye segment analysis system revealed that ACAW decreased with age, especially in the lateral quadrant. The significantly more marked narrowness of ACAW in females older than middle age may be related to the high incidence of angle closure glaucoma in elderly females.
authors.affiliation: Department of Ophthalmology, Yamanashi Medical University, Japan.
authors.forename: H B
authors.initials: HB
authors.lastname: Chen
authors.forename: K
authors.initials: K
authors.lastname: Kashiwagi
authors.forename: S
authors.initials: S
authors.lastname: Yamabayashi
authors.forename: T
authors.initials: T
authors.lastname: Kinoshita
authors.forename: B
authors.initials: B
authors.lastname: Ou
authors.forename: S
authors.initials: S
authors.lastname: Tsukahara
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D000867:Anterior Chamber / Q000033:anatomy & histology*; D000886:Anthropometry; D001699:Biometry; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012727:Sex Characteristics