title: Influence of anterior segment biometric parameters on the anterior chamber angle width in eyes with angle closure.
abstract: OBJECTIVE
  To predict angle narrowing in eyes with angle closure in a Japanese population using anterior segment optical coherence tomography (AS-OCT) quantitative parameters.
  
  
  METHODS
  AS-OCT was used to examine 118 eyes of 118 patients with angle closure and 40 eyes of 40 patients with open angle under dark conditions. After measuring the angle opening distance 500 (AOD500), anterior chamber depth, iris thickness (IT), iris convexity (IC), pupil diameter, anterior chamber width, and crystalline lens rise, multivariate regression analyses were performed for the AOD500 in each group.
  
  
  RESULTS
  With the exception of IT, significant differences were observed between the AS-OCT parameters for the angle closure and open-angle groups. Anterior chamber depth, IT, and IC were the explanatory variables associated with AOD500 for each group (P≤0.001). A significant negative association was found between IT and IC only in the angle-closure group (P<0.001).
  
  
  CONCLUSIONS
  This study quantitatively confirmed that shallow anterior chamber depth was a major mechanism of angle narrowing, and that both IT and IC had a strong impact on angle narrowing. Moreover, the negative association found between IT and IC in only the angle closure group indicated the existence of the stretch force placed on the iris by relative pupillary block.
authors.affiliation: Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Matsuki
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Hirose
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Ito
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hata
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Hirami
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kurimoto
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D044466:Asian People; D001699:Biometry; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000503:physiopathology*; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000473:pathology*; D007908:Lens, Crystalline / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology; D041623:Tomography, Optical Coherence / Q000379:methods