title: Anterior chamber depth measurement as a screening tool for primary angle-closure glaucoma in an East Asian population.
abstract: OBJECTIVE
  To evaluate anterior chamber depth measurement as a method of screening for primary angle-closure glaucoma in an East Asian population.
  
  
  METHODS
  Two-phase, cross-sectional, community-based study.
  
  
  METHODS
  Rural and urban locations in the Hovsgol and Omnogobi provinces, Mongolia.
  
  
  METHODS
  Nine hundred forty-two (94.2%) of 1000 individuals in Hovsgol(1995) and 775 (96.9%) of 1000 individuals in Omnogobi (1997) aged 40 years or older were examined.
  
  
  METHODS
  Anterior chamber depth was measured by optical pachymetry, slitlamp-mounted A-mode ultrasound, and handheld ultrasound. Gonioscopy was used to detect occludable angles, defined as one in which the trabecular meshwork was visible for less than 90 degrees of angle circumference. Primary open-angle glaucoma was diagnosed in subjects with an occludable angle and glaucomatous optic neuropathy with visual morbidity. The area under the curve in a receiver operating characteristic plot was used to compare test performance.
  
  
  RESULTS
  Optical pachymetry outperformed the slitlamp-mounted ultrasound method of anterior chamber depth measurement (area under the curve, 0.93 and 0.90, respectively; z test, P = .001). Handheld ultrasound (area under the curve, 0.86) was inferior to optical measurement (z test, P = .001) but did not differ significantly from slitlamp ultrasound (z test, P = .06). The optical method gave sensitivity of 85% and specificity of 84% at a screening cutoff of less than 2.22 mm for detecting occludable angles.
  
  
  CONCLUSIONS
  Measurement of axial anterior chamber depth can detect occludable angles in this Asian population and therefore may have a role in population screening for primary angle-closure glaucoma.
authors.affiliation: Department of Preventive Ophthalmology, Institute of Ophthalmology, University College London, England.
authors.forename: J G
authors.initials: JG
authors.lastname: Devereux
authors.forename: P J
authors.initials: PJ
authors.lastname: Foster
authors.forename: J
authors.initials: J
authors.lastname: Baasanhu
authors.forename: D
authors.initials: D
authors.lastname: Uranchimeg
authors.forename: P S
authors.initials: PS
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Erdenbeleig
authors.forename: D
authors.initials: D
authors.lastname: Machin
authors.forename: G J
authors.initials: GJ
authors.lastname: Johnson
authors.forename: P H
authors.initials: PH
authors.lastname: Alsbirk
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000000981:diagnostic imaging / Q000473:pathology*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000208:ethnology*; D006068:Gonioscopy / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D008986:Mongolia / Q000208:ethnology; D015203:Reproducibility of Results; D012424:Rural Population; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014505:Urban Population