title: Agreement among graders on Heidelberg retina tomograph (HRT) topographic change analysis (TCA) glaucoma progression interpretation.
abstract: OBJECTIVE
  To evaluate agreement among experts of Heidelberg retina tomography's (HRT) topographic change analysis (TCA) printout interpretations of glaucoma progression and explore methods for improving agreement.
  
  
  METHODS
  109 eyes of glaucoma, glaucoma suspect and healthy subjects with ≥5 visits and 2 good quality HRT scans acquired at each visit were enrolled. TCA printouts were graded as progression or non-progression. Each grader was presented with 2 sets of tests: a randomly selected single test from each visit and both tests from each visit. Furthermore, the TCA printouts were classified with grader's individual criteria and with predefined criteria (reproducible changes within the optic nerve head, disregarding changes along blood vessels or at steep rim locations and signs of image distortion). Agreement among graders was modelled using common latent factor measurement error structural equation models for ordinal data.
  
  
  RESULTS
  Assessment of two scans per visit without using the predefined criteria reduced overall agreement, as indicated by a reduction in the slope, reflecting the correlation with the common factor, for all graders with no effect on reducing the range of the intercepts between the graders. Using the predefined criteria improved grader agreement, as indicated by the narrower range of intercepts among the graders compared with assessment using individual grader's criteria.
  
  
  CONCLUSIONS
  A simple set of predefined common criteria improves agreement between graders in assessing TCA progression. The inclusion of additional scans from each visit does not improve the agreement. We, therefore, recommend setting standardised criteria for TCA progression evaluation.
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Eye Clinic, DiNOGMI, University of Genoa, Genoa, Italy.
authors.forename: Michele M
authors.initials: MM
authors.lastname: Iester
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Gadi
authors.initials: G
authors.lastname: Wollstein
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bilonick
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Larry
authors.initials: L
authors.lastname: Kagemann
authors.affiliation: Department of Ophthalmology, UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Schuman
mesh_terms: D003941:Diagnostic Techniques, Ophthalmological; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009798:Ocular Hypertension / Q000145:classification / Q000175:diagnosis / Q000503:physiopathology; D019721:Ophthalmoscopes; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D015203:Reproducibility of Results; D014054:Tomography; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields
keywords: Glaucoma; Imaging