title: Comparative study of retinal nerve fibre layer measurement by RTVue OCT and GDx VCC.
abstract: OBJECTIVE
  To evaluate the diagnostic performances and correlations of retinal nerve fibre layer (RNFL) thickness measured by RTVue OCT and GDx variable corneal compensation (VCC).
  
  
  METHODS
  The total and regional RNFL thickness were measured by RTVue OCT and GDx VCC in 62 normal eyes and 72 glaucomatous eyes of Chinese subjects. The RNFL thickness profiles of normal and glaucomatous eyes by RTVue OCT are plotted. Correlations of RNFL thickness measured by RTVue OCT and GDx VCC were assessed using the Pearson correlation. The discriminating abilities of the two techniques for detection of glaucoma were compared by the area under the receiver operating characteristic curves (AUC).
  
  
  RESULTS
  RTVue OCT demonstrated double hump patterns in the RNFL profiles. In both normal and glaucomatous subjects, the peaks were located in the superotemporal (ST) and inferotemporal (IT) regions, and the troughs were located at the nasal (NU+NL) and temporal (TU+TL) regions. Despite poor agreement, a high correlation (r=0.821) was found between the mean RNFL measurements by RTVue OCT and GDx VCC. For RTVue OCT, the highest AUCs were mean RNFL (AUC=0.914) and inferior mean RNFL (AUC=0.909). The nerve fibre indicator (AUC=0.856) and inferior RNFL (AUC=0.852) achieved the highest AUCs among all the GDx VCC measurements. The mean RNFL in RTVue OCT had the greatest AUC in the two devices. There was a significant difference in comparing the AUCs of the mean RNFL thickness obtained by RTVue OCT and GDx VCC (p=0.009).
  
  
  CONCLUSIONS
  Although there were absolute value differences in RNFL thickness, a high correlation was observed between RTVue OCT and GDx VCC. RTVue OCT shows a reasonable ability to distinguish normal from glaucomatous eyes.
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Wang
authors.forename: Shuning
authors.initials: S
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Fu
authors.forename: Gewei
authors.initials: G
authors.lastname: Wu
authors.forename: Dapeng
authors.initials: D
authors.lastname: Mu
authors.forename: Songfeng
authors.initials: S
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Ningli
authors.initials: N
authors.lastname: Wang
mesh_terms: D000328:Adult; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology; D055351:Retinal Neurons / Q000473:pathology*; D057109:Scanning Laser Polarimetry / Q000295:instrumentation* / Q000379:methods; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000379:methods; D014794:Visual Fields / Q000502:physiology