title: Development of a score and probability estimate for detecting angle closure based on anterior segment optical coherence tomography.
abstract: OBJECTIVE
  To develop a score along with an estimated probability of disease for detecting angle closure based on anterior segment optical coherence tomography (AS OCT) imaging.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A total of 2047 subjects 50 years of age and older were recruited from a community polyclinic in Singapore. All subjects underwent standardized ocular examination including gonioscopy and imaging by AS OCT (Carl Zeiss Meditec). Customized software (Zhongshan Angle Assessment Program) was used to measure AS OCT parameters. Complete data were available for 1368 subjects. Data from the right eyes were used for analysis. A stepwise logistic regression model with Akaike information criterion was used to generate a score that then was converted to an estimated probability of the presence of gonioscopic angle closure, defined as the inability to visualize the posterior trabecular meshwork for at least 180 degrees on nonindentation gonioscopy.
  
  
  RESULTS
  Of the 1368 subjects, 295 (21.6%) had gonioscopic angle closure. The angle closure score was calculated from the shifted linear combination of the AS OCT parameters. The score can be converted to an estimated probability of having angle closure using the relationship: estimated probability = e(score)/(1 + e(score)), where e is the natural exponential. The score performed well in a second independent sample of 178 angle-closure subjects and 301 normal controls, with an area under the receiver operating characteristic curve of 0.94.
  
  
  CONCLUSIONS
  A score derived from a single AS OCT image, coupled with an estimated probability, provides an objective platform for detection of angle closure.
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Center, Singapore, Republic of Singapore; Centre for Quantitative Medicine, Office of Clinical Sciences Duke-NUS Graduate Medical School, Singapore, Republic of Singapore.
authors.forename: Monisha E
authors.initials: ME
authors.lastname: Nongpiur
authors.affiliation: Centre for Quantitative Medicine, Office of Clinical Sciences Duke-NUS Graduate Medical School, Singapore, Republic of Singapore; Department of Statistics and Applied Probability, National University of Singapore, Singapore, Republic of Singapore.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Haaland
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Center, Singapore, Republic of Singapore.
authors.forename: Shamira A
authors.initials: SA
authors.lastname: Perera
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: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Center, Singapore, Republic of Singapore.
authors.forename: Lisandro M
authors.initials: LM
authors.lastname: Sakata
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Center, Singapore, Republic of Singapore.
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Center, 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: D000869:Anterior Eye Segment / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012372:ROC Curve; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000706:statistics & numerical data*