title: Color Reflectivity Discretization Analysis of OCT Images in the Detection of Glaucomatous Nerve Fiber Layer Defects.
abstract: OBJECTIVE
  To compare the ability of Cirrus retinal nerve fiber layer (RNFL) thickness and the Color Reflectivity Discretization Analysis (CORDA), a novel optical coherence tomography (OCT) analysis method, to differentiate between normal subjects, glaucoma suspects, and glaucoma patients.
  
  
  METHODS
  Analysis of peripapillary OCT images using Cirrus SD-OCT (optic nerve head cube 200 × 200 protocol) and postacquisition CORDA analysis of peripapillary RNFL B-scan images was performed. In total, 291 eyes of 148 subjects (94 normal eyes, 100 primary open-angle glaucoma suspect eyes, and 97 eyes with primary open-angle glaucoma) were included. Area under the receiver operating characteristic curve was estimated for each region and method (Cirrus vs. CORDA) for differentiating eyes with glaucoma, and those that are glaucoma suspect, from normal eyes.
  
  
  RESULTS
  CORDA HR1 parameter discriminated glaucoma patients from normal subjects more accurately than Cirrus RNFL thickness in nasal (P = 0.003) and temporal (P = 0.001) regions. HR1 showed greater area under the receiver operating characteristic curve than Cirrus RNFL thickness when discriminating glaucoma suspects from normal subjects in the superior (P = 0.02), nasal (P = 0.003), and temporal (P = 0.001) regions. Both were similar for mean and the inferior regions.
  
  
  CONCLUSIONS
  In this study, the novel CORDA HR1 differentiated between normal subjects and glaucoma suspects more accurately than Cirrus RNFL, and in temporal and nasal regions when discriminating between normal and glaucomatous eyes. CORDA analysis may improve the diagnostic accuracy of Cirrus OCT for glaucoma and glaucoma suspects.
authors.affiliation: *Northern Virginia Ophthalmology Associates, Falls Church, VA §Diopsys Inc., Pine Brook, NJ ‡Division of Biostatistics, Thomas Jefferson University †Wills Eye Hospital, Glaucoma Research Center, Philadelphia, PA.
authors.forename: Sonya B
authors.initials: SB
authors.lastname: Shah
authors.forename: Alberto G
authors.initials: AG
authors.lastname: Garcia
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Leiby
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Cox
authors.forename: L Jay
authors.initials: LJ
authors.lastname: Katz
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Myers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009798:Ocular Hypertension / Q000175:diagnosis; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult