title: Diagnostic classification of macular ganglion cell and retinal nerve fiber layer analysis: differentiation of false-positives from glaucoma.
abstract: OBJECTIVE
  To investigate the rate and associated factors of false-positive diagnostic classification of ganglion cell analysis (GCA) and retinal nerve fiber layer (RNFL) maps, and characteristic false-positive patterns on optical coherence tomography (OCT) deviation maps.
  
  
  METHODS
  Prospective, cross-sectional study.
  
  
  METHODS
  A total of 104 healthy eyes of 104 normal participants.
  
  
  METHODS
  All participants underwent peripapillary and macular spectral-domain (Cirrus-HD, Carl Zeiss Meditec Inc, Dublin, CA) OCT scans. False-positive diagnostic classification was defined as yellow or red color-coded areas for GCA and RNFL maps. Univariate and multivariate logistic regression analyses were used to determine associated factors. Eyes with abnormal OCT deviation maps were categorized on the basis of the shape and location of abnormal color-coded area. Differences in clinical characteristics among the subgroups were compared.
  
  
  METHODS
  (1) The rate and associated factors of false-positive OCT maps; (2) patterns of false-positive, color-coded areas on the GCA deviation map and associated clinical characteristics.
  
  
  RESULTS
  Of the 104 healthy eyes, 42 (40.4%) and 32 (30.8%) showed abnormal diagnostic classifications on any of the GCA and RNFL maps, respectively. Multivariate analysis revealed that false-positive GCA diagnostic classification was associated with longer axial length and larger fovea-disc angle, whereas longer axial length and smaller disc area were associated with abnormal RNFL maps. Eyes with abnormal GCA deviation map were categorized as group A (donut-shaped round area around the inner annulus), group B (island-like isolated area), and group C (diffuse, circular area with an irregular inner margin in either). The axial length showed a significant increasing trend from group A to C (P=0.001), and likewise, the refractive error was more myopic in group C than in groups A (P=0.015) and B (P=0.014). Group C had thinner average ganglion cell-inner plexiform layer thickness compared with other groups (group A=B>C, P=0.004).
  
  
  CONCLUSIONS
  Abnormal OCT diagnostic classification should be interpreted with caution, especially in eyes with long axial lengths, large fovea-disc angles, and small optic discs. Our findings suggest that the characteristic patterns of OCT deviation map can provide useful clues to distinguish glaucomatous changes from false-positive findings.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea; Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ko Eun
authors.initials: KE
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea; Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea. Electronic address: neuroprotect@gmail.com.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Jeoung
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea; Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea; Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Dong Myung
authors.initials: DM
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea; Department of Ophthalmology, Seoul National University Boramae Hospital, Seoul, Korea.
authors.forename: Seok Hwan
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000145:classification / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000145:classification / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D055815:Young Adult