title: Automated volumetric evaluation of stereoscopic disc photography.
abstract: OBJECTIVE
  To develop a fully automated algorithm (AP) to perform a volumetric measure of the optic disc using conventional stereoscopic optic nerve head (ONH) photographs, and to compare algorithm-produced parameters with manual photogrammetry (MP), scanning laser ophthalmoscope (SLO) and optical coherence tomography (OCT) measurements.
  
  
  METHODS
  One hundred twenty-two stereoscopic optic disc photographs (61 subjects) were analyzed. Disc area, rim area, cup area, cup/disc area ratio, vertical cup/disc ratio, rim volume and cup volume were automatically computed by the algorithm. Latent variable measurement error models were used to assess measurement reproducibility for the four techniques.
  
  
  RESULTS
  AP had better reproducibility for disc area and cup volume and worse reproducibility for cup/disc area ratio and vertical cup/disc ratio, when the measurements were compared to the MP, SLO and OCT methods.
  
  
  CONCLUSIONS
  AP provides a useful technique for an objective quantitative assessment of 3D ONH structures.
authors.affiliation: UPMC Eye Center, Ophthalmology and Visual Science Research Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Gadi
authors.initials: G
authors.lastname: Wollstein
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bilonick
authors.forename: Larry
authors.initials: L
authors.lastname: Kagemann
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Craig
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
authors.forename: Joel S
authors.initials: JS
authors.lastname: Schuman
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009898:Optic Disk / Q000033:anatomy & histology*; D010363:Pattern Recognition, Automated / Q000379:methods*; D010780:Photogrammetry / Q000379:methods*; D010781:Photography / Q000379:methods*; D042262:Retinoscopy / Q000379:methods*