title: Differentiation of compressive from glaucomatous optic neuropathy with spectral-domain optical coherence tomography.
abstract: OBJECTIVE
  To compare optic disc topography in eyes with compressive optic neuropathy (CON) and open-angle glaucoma (OAG) using spectral-domain (SD) optical coherence tomography (OCT) and Heidelberg retinal tomograph (HRT) (Heidelberg Engineering GmbH, Heidelberg, Germany).
  
  
  METHODS
  Cross-sectional, observational study.
  
  
  METHODS
  A total of 200 eyes from 123 patients with CON (69 eyes) or OAG (58 eyes) and controls (73 eyes).
  
  
  METHODS
  Univariate and multivariate analyses of HRT parameters, SD-OCT circumpapillary retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters.
  
  
  METHODS
  Circumpapillary RNFL, OCT ONH parameters, and HRT parameters.
  
  
  RESULTS
  The univariate analysis of OCT parameters demonstrated significant differences between the temporal and nasal quadrants; clock hours 3 (55 vs. 73 μm), 4, 8 (93.9 vs. 70.7 μm), 9, and 10; vertical cup-to-disc ratio (C:D) (0.6 vs. 0.8) and cup volume (0.2 vs. 0.5) (P<0.001) between patients with CON and OAG, respectively. The CON discs were significantly different from normal discs for all OCT parameters except cup volume. The CON discs were not significantly different from normal discs for HRT parameters, except for mean RNFL thickness and cup shape measure. The OAG discs were significantly different from normal discs in all HRT and OCT parameters (P<0.001). Multivariate analysis demonstrated that the OCT 3 o'clock temporal sector, average C:D ratio, vertical C:D ratio, and cup volume measurements were able to differentiate OAG from CON.
  
  
  CONCLUSIONS
  Compressive optic neuropathy is associated with significantly thinner nasal and temporal sectors compared with OAG, whereas OAG results in larger cups and cup volume with OCT measurements. The Heidelberg retinal tomograph is not able to differentiate CON from normal discs.
authors.affiliation: Department of Ophthalmology, University of Auckland, Auckland, New Zealand. Electronic address: h.daneshmeyer@auckland.ac.nz.
authors.forename: Helen V
authors.initials: HV
authors.lastname: Danesh-Meyer
authors.affiliation: Department of Ophthalmology, University of Auckland, Auckland, New Zealand.
authors.forename: Joel
authors.initials: J
authors.lastname: Yap
authors.affiliation: Department of Medicine, University of Otago, Dunedin, New Zealand.
authors.forename: Christopher
authors.initials: C
authors.lastname: Frampton
authors.affiliation: Shiley Eye Center, University of California San Diego, San Diego, California.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Savino
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis*; D009412:Nerve Fibers / Q000473:pathology*; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology