title: Discriminating between normal and glaucomatous eyes using the Heidelberg Retina Tomograph, GDx Nerve Fiber Analyzer, and Optical Coherence Tomograph.
abstract: OBJECTIVE
  To compare the ability of 3 instruments, the Heidelberg Retina Tomograph (HRT), the GDx Nerve Fiber Analyzer (GDx), and the Optical Coherence Tomograph (OCT), to discriminate between healthy eyes and eyes with early to moderate glaucomatous visual field loss.
  
  
  METHODS
  Forty-one patients with early to moderate glaucomatous visual field loss and 50 healthy subjects were included in the study. The HRT, GDx, and OCT imaging and visual field testing were completed on 1 eye from each subject within a 6-month interval. Statistical differences in sensitivity at fixed specificities of 85%, 90%, and 95% were evaluated. In addition, areas under the receiver operating characteristic (ROC) curve were compared.
  
  
  RESULTS
  No significant differences were found between the area under the ROC curve and the best parameter from each instrument: OCT thickness at the 5-o'clock inferior temporal position (mean +/- SE, 0.87 +/- 0.04), HRT mean height contour in the nasal inferior region (mean +/- SE, 0.86 +/- 0.04), and GDx linear discriminant function (mean +/- SE, 0.84 +/- 0.04). Twelve HRT, 2 GDx, and 9 OCT parameters had an area under the ROC curve of at least 0.81. At a fixed specificity of 90%, significant differences were found between the sensitivity of OCT thickness at the 5-o'clock inferior temporal position (71%) and parameters with sensitivities less than 52%. Qualitative assessment of stereophotographs resulted in a sensitivity of 80%.
  
  
  CONCLUSIONS
  Although the area under the ROC curves was similar among the best parameters from each instrument, qualitative assessment of stereophotographs and measurements from the OCT and HRT generally had higher sensitivities than measurements from the GDx.
authors.affiliation: Glaucoma Center, Department of Ophthalmology, University of California-San Diego, La Jolla, CA 92093-0946, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Zangwill
authors.forename: C
authors.initials: C
authors.lastname: Bowd
authors.forename: C C
authors.initials: CC
authors.lastname: Berry
authors.forename: J
authors.initials: J
authors.lastname: Williams
authors.forename: E Z
authors.initials: EZ
authors.lastname: Blumenthal
authors.forename: C A
authors.initials: CA
authors.lastname: Sánchez-Galeana
authors.forename: C
authors.initials: C
authors.lastname: Vasile
authors.forename: R N
authors.initials: RN
authors.lastname: Weinreb
mesh_terms: D000328:Adult; D000368:Aged; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007368:Interferometry; D007429:Intraocular Pressure; D008027:Light; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D012372:ROC Curve; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012680:Sensitivity and Specificity; D014054:Tomography / Q000379:methods; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields