title: Retinal nerve fibre layer imaging: comparison of Cirrus optical coherence tomography and Heidelberg retinal tomograph 3.
abstract: BACKGROUND
  The purpose of this study was to analyze the relationship between retinal nerve fibre layer thickness measured by spectral domain optical coherence tomography and confocal scanning laser ophthalmoscope.
  
  
  METHODS
  Prospective, cross-sectional study. Hospital setting.
  
  
  METHODS
  One hundred seventy-three subjects (85 glaucoma and 88 normal subjects).
  
  
  METHODS
  One eye from each individual was selected randomly for imaging by the spectral domain Cirrus optical coherence tomography and Heidelberg retinal tomograph 3.
  
  
  METHODS
  Global thickness and measurements at the four quadrants around the optic disc.
  
  
  RESULTS
  Measurements as determined by Heidelberg retinal tomograph 3 were significantly larger than measurements done by Cirrus optical coherence tomography (respectively in mm, for global thickness: 200.0 ± 87.2 and 80.7 ± 14.7; for temporal quadrant: 75.3 ± 31.9 and 59.1 ± 13.8; for superior quadrant: 223.2 ± 128.4 and 97.7 ± 20.9; for nasal quadrant: 208.0 ± 102.9 and 66.8 ± 11.8; and for inferior quadrant: 224.4 ± 116.9 and 99.1 ± 26.6, for all P < 0.01). Significant correlation was found for all measurements (P ≤ 0.009), but a pattern of proportional bias was demonstrated. The agreement of categorical classification (within normal limits, borderline or outside normal limits) ranged between poor and fair.
  
  
  CONCLUSIONS
  The thickness easurements by the two technologies are strongly correlated but significantly different. The differences are substantial and proportional to the retinal nerve fibre layer thickness. The normative diagnostic classification of the two technologies may not agree. The results preclude interchangeable use of these measurements in clinical practice.
authors.affiliation: Glaucoma Unit, Sydney Eye Hospital, Sydney, New South Wales, Australia; Department of Ophthalmology, Soroka University Medical Centre, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Assaf
authors.initials: A
authors.lastname: Kratz
authors.forename: Ridia
authors.initials: R
authors.lastname: Lim
authors.forename: Ryan
authors.initials: R
authors.lastname: Rush
authors.forename: Saumil
authors.initials: S
authors.lastname: Sheth
authors.forename: Ivan
authors.initials: I
authors.lastname: Goldberg
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular
keywords: Cirrus optical coherence tomography; Heidelberg retinal tomograph 3; retinal nerve fibre layer thickness