title: Retinal nerve fiber layer imaging with spectral-domain optical coherence tomography a study on diagnostic agreement with Heidelberg Retinal Tomograph.
abstract: OBJECTIVE
  To evaluate and compare the diagnostic agreement and performance for glaucoma detection between a confocal scanning laser ophthalmoscope and a spectral-domain optical coherence tomograph (OCT).
  
  
  METHODS
  Prospective, cross-sectional study.
  
  
  METHODS
  One hundred fifty-five subjects (79 glaucoma and 76 normal subjects).
  
  
  METHODS
  One eye from each individual was selected randomly for optic disc and retinal nerve fiber layer (RNFL) imaging by the Heidelberg Retinal Tomograph (HRT; Heidelberg Engineering, GmbH, Dossenheim, Germany) and the Spectralis OCT (Heidelberg Engineering), respectively. Glaucoma was defined based on the presence of visual field defects with the Humphrey visual field analyzer (Carl Zeiss Meditec, Dublin, CA). The agreement of the categorical classification ("within normal limits," "borderline," and "outside normal limits") at the temporal, superotemporal, superonasal, nasal, inferonasal and inferotemporal sectors of the optic disc were evaluated (kappa statistics). The diagnostic sensitivity and specificity between optic disc and RNFL assessment were compared (McNemar's statistics). Area under the receiver operating characteristic curve (AUC) of OCT RNFL and HRT optic disc parameters were computed after adjustment of age, axial length, and optic disc area.
  
  
  METHODS
  Agreement of categorical classification, AUC of optic disc, and RNFL parameters.
  
  
  RESULTS
  The agreement of categorical classification between HRT and Spectralis OCT were fair to moderate (kappa ranged between 0.30 and 0.53) except for global (kappa = 0.63) and inferotemporal (kappa = 0.68) measurements. Defining glaucoma as having "outside normal limits" in the global and/or in >or=1 of the sectoral measurements, the respective sensitivities of Spectralis OCT and HRT were 91.1% and 79.8% (P = 0.012) at a similar level of specificity (97.4% and 94.7%). The AUC of OCT global RNFL thickness (0.978) was greater than those of HRT global rim area (0.905), vertical cup-disc ratio (0.857), rim-disc area ratio (0.897), and multivariate discriminant analysis (0.880-0.925; all with P<or=0.028) after covariates adjustment.
  
  
  CONCLUSIONS
  The diagnostic classification provided in the HRT and Spectralis OCT analysis report may not agree. At a comparable level of specificity, Spectralis OCT RNFL measurement attained a higher sensitivity than HRT optic disc measurement.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, PR China.
authors.forename: Christopher Kai-shun
authors.initials: CK
authors.lastname: Leung
authors.forename: Cong
authors.initials: C
authors.lastname: Ye
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.forename: Carol Yim Lui
authors.initials: CY
authors.lastname: Cheung
authors.forename: Quanliang
authors.initials: Q
authors.lastname: Qiu
authors.forename: Shu
authors.initials: S
authors.lastname: Liu
authors.forename: Guihua
authors.initials: G
authors.lastname: Xu
authors.forename: Dennis Shun Chiu
authors.initials: DS
authors.lastname: Lam
mesh_terms: D000328:Adult; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009887:Ophthalmoscopy / Q000379:methods*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*; D058609:Visual Field Tests; D014794:Visual Fields