title: Comparison of EyeCam and anterior segment optical coherence tomography in detecting angle closure.
abstract: OBJECTIVE
  To compare the diagnostic performance of EyeCam (Clarity Medical Systems, Pleasanton, CA, USA) and anterior segment optical coherence tomography (ASOCT, Visante; Carl Zeiss Meditec, Dublin, CA, USA) in detecting angle closure, using gonioscopy as the reference standard.
  
  
  METHODS
  Ninety-eight phakic patients, recruited from a glaucoma clinic, underwent gonioscopy by a single examiner, and EyeCam and ASOCT imaging by another examiner. Another observer, masked to gonioscopy findings, graded EyeCam and ASOCT images. For both gonioscopy and EyeCam, a closed angle in a particular quadrant was defined if the posterior trabecular meshwork was not visible. For ASOCT, angle closure was defined by any contact between the iris and angle anterior to the scleral spur. An eye was diagnosed as having angle closure if ≥2 quadrants were closed. Agreement and area under the receiver operating characteristic curves (AUC) were evaluated.
  
  
  RESULTS
  The majority of subjects were Chinese (69/98, 70.4%) with a mean age of 60.6 years. Angle closure was diagnosed in 39/98 (39.8%) eyes with gonioscopy, 40/98 (40.8%) with EyeCam and 56/97 (57.7%) with ASOCT. The agreement (kappa statistic) for angle closure diagnosis for gonioscopy versus EyeCam was 0.89; gonioscopy versus ASOCT and EyeCam versus ASOCT were both 0.56. The AUC for detecting eyes with gonioscopic angle closure with EyeCam was 0.978 (95% CI: 0.93-1.0) and 0.847 (95% CI: 0.76-0.92, p < 0.01) for ASOCT.
  
  
  CONCLUSIONS
  The diagnostic performance of EyeCam was better than ASOCT in detecting angle closure when gonioscopic grading was used as the reference standard. The agreement between the two imaging modalities was moderate.
authors.affiliation: Singapore Eye Research Institute & Singapore National Eye Center, Singapore.
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.forename: Tin A
authors.initials: TA
authors.lastname: Tun
authors.forename: Shamira A
authors.initials: SA
authors.lastname: Perera
mesh_terms: D000869:Anterior Eye Segment / Q000473:pathology*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000295:instrumentation*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation*; D014065:Tonometry, Ocular