title: Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma.
abstract: BACKGROUND
  Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma.
  
  
  OBJECTIVE
  To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma.
  
  
  METHODS
  Cross-sectional analysis.
  
  
  METHODS
  35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations.
  
  
  METHODS
  Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR).
  
  
  RESULTS
  Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P < 0.001 for all comparisons). AUCs of all HD-OCT ONH parameters (0.90-0.97 in perimetric and 0.62-0.71 in preperimetric glaucoma) were comparable (P > 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma.
  
  
  CONCLUSIONS
  ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma.
authors.affiliation: VST Glaucoma Center, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Viquar Unnisa
authors.initials: VU
authors.lastname: Begum
authors.affiliation: VST Glaucoma Center, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Uday Kumar
authors.initials: UK
authors.lastname: Addepalli
authors.affiliation: VST Glaucoma Center, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Sirisha
authors.initials: S
authors.lastname: Senthil
authors.affiliation: VST Glaucoma Center, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Chandra Sekhar
authors.initials: CS
authors.lastname: Garudadri
authors.affiliation: VST Glaucoma Center, L. V. Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Harsha Laxmana
authors.initials: HL
authors.lastname: Rao
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D011446:Prospective Studies; D012372:ROC Curve; D012160:Retina / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields