title: Reference Standard Test and the Diagnostic Ability of Spectral Domain Optical Coherence Tomography in Glaucoma.
abstract: OBJECTIVE
  To evaluate the relationship between the reference standard used to diagnose glaucoma and the diagnostic ability of spectral domain optical coherence tomograph (SDOCT).
  
  
  METHODS
  In a cross-sectional study, 280 eyes of 175 consecutive subjects, referred to a tertiary eye care center for glaucoma evaluation, underwent optic disc photography, visual field (VF) examination, and SDOCT examination. The cohort was divided into glaucoma and control groups based on 3 reference standards for glaucoma diagnosis: first based on the optic disc classification (179 glaucoma and 101 control eyes), second on VF classification (glaucoma hemifield test outside normal limits and pattern SD with P-value of <5%, 130 glaucoma and 150 control eyes), and third on the presence of both glaucomatous optic disc and glaucomatous VF (125 glaucoma and 155 control eyes). Relationship between the reference standards and the diagnostic parameters of SDOCT were evaluated using areas under the receiver operating characteristic curve, sensitivity, and specificity.
  
  
  RESULTS
  Areas under the receiver operating characteristic curve and sensitivities of most of the SDOCT parameters obtained with the 3 reference standards (ranging from 0.74 to 0.88 and 72% to 88%, respectively) were comparable (P>0.05). However, specificities of SDOCT parameters were significantly greater (P<0.05) with optic disc classification as reference standard (74% to 88%) compared with VF classification as reference standard (57% to 74%).
  
  
  CONCLUSIONS
  Diagnostic parameters of SDOCT that was significantly affected by reference standard was the specificity, which was greater with optic disc classification as the reference standard. This has to be considered when comparing the diagnostic ability of SDOCT across studies.
authors.affiliation: *VST Glaucoma Center †Center for Clinical Epidemiology and Biostatistics, LV Prasad Eye Institute, Banjara Hills, Hyderabad, India.
authors.forename: Harsha L
authors.initials: HL
authors.lastname: Rao
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Yadav
authors.forename: Uday K
authors.initials: UK
authors.lastname: Addepalli
authors.forename: Viquar U
authors.initials: VU
authors.lastname: Begum
authors.forename: Sirisha
authors.initials: S
authors.lastname: Senthil
authors.forename: Nikhil S
authors.initials: NS
authors.lastname: Choudhari
authors.forename: Chandra S
authors.initials: CS
authors.lastname: Garudadri
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000473:pathology*; D010781:Photography; D012372:ROC Curve; D012015:Reference Standards; D012165:Retinal Ganglion Cells / Q000473:pathology; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000592:standards*; D014794:Visual Fields / Q000502:physiology*