title: Anterior Segment Imaging Predicts Incident Gonioscopic Angle Closure.
abstract: OBJECTIVE
  To investigate the incidence of gonioscopic angle closure after 4 years in subjects with gonioscopically open angles but varying degrees of angle closure detected on anterior segment optical coherence tomography (AS OCT; Visante; Carl Zeiss Meditec, Dublin, CA) at baseline.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Three hundred forty-two subjects, mostly Chinese, 50 years of age or older, were recruited, of whom 65 were controls with open angles on gonioscopy and AS OCT at baseline, and 277 were cases with baseline open angles on gonioscopy but closed angles (1-4 quadrants) on AS OCT scans.
  
  
  METHODS
  All subjects underwent gonioscopy and AS OCT at baseline (horizontal and vertical single scans) and after 4 years. The examiner performing gonioscopy was masked to the baseline and AS OCT data. Angle closure in a quadrant was defined as nonvisibility of the posterior trabecular meshwork by gonioscopy and visible iridotrabecular contact beyond the scleral spur in AS OCT scans.
  
  
  METHODS
  Gonioscopic angle closure in 2 or 3 quadrants after 4 years.
  
  
  RESULTS
  There were no statistically significant differences in age, ethnicity, or gender between cases and controls. None of the control subjects demonstrated gonioscopic angle closure after 4 years. Forty-eight of the 277 subjects (17.3%; 95% confidence interval [CI], 12.8-23; P < 0.0001) with at least 1 quadrant of angle closure on AS OCT at baseline demonstrated gonioscopic angle closure in 2 or more quadrants, whereas 28 subjects (10.1%; 95% CI, 6.7-14.6; P < 0.004) demonstrated gonioscopic angle closure in 3 or more quadrants after 4 years. Individuals with more quadrants of angle closure on baseline AS OCT scans had a greater likelihood of gonioscopic angle closure developing after 4 years (P < 0.0001, chi-square test for trend for both definitions of angle closure).
  
  
  CONCLUSIONS
  Anterior segment OCT imaging at baseline predicts incident gonioscopic angle closure after 4 years among subjects who have gonioscopically open angles and iridotrabecular contact on AS OCT at baseline.
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-NUS Graduate Medical School, Singapore, Republic of Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore.
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore.
authors.forename: Jayant V
authors.initials: JV
authors.lastname: Iyer
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Narayanaswamy
authors.affiliation: Duke-NUS Graduate Medical School, Singapore, Republic of Singapore.
authors.forename: Yingke
authors.initials: Y
authors.lastname: He
authors.affiliation: Federal University of Parana, Curitiba, Brazil.
authors.forename: Lisandro M
authors.initials: LM
authors.lastname: Sakata
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore; Xiamen Eye Center, Xiamen University, Xiamen, China.
authors.forename: Renyi
authors.initials: R
authors.lastname: Wu
authors.affiliation: Wilmer Eye Institute, Dana Center for Preventive Ophthalmology, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Dianna
authors.initials: D
authors.lastname: Liu
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-NUS Graduate Medical School, Singapore, Republic of Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore.
authors.forename: Monisha E
authors.initials: ME
authors.lastname: Nongpiur
authors.affiliation: Wilmer Eye Institute, Dana Center for Preventive Ophthalmology, Johns Hopkins University, Baltimore, Maryland.
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore; Duke-NUS Graduate Medical School, Singapore, Republic of Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore. Electronic address: aung.tin@snec.com.sg.
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
mesh_terms: D000368:Aged; D000869:Anterior Eye Segment / Q000473:pathology*; D044466:Asian People / Q000208:ethnology; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000208:ethnology; D005902:Glaucoma, Open-Angle / Q000208:ethnology / Q000473:pathology; D006068:Gonioscopy; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology