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BACKGROUND: The propose of this study was to analyze the relationship between retinal nerve fibre layer (RNFL) thickness measured by spectral domain optical coherence tomography and confocal scanning laser ophthalmoscope. DESIGN: Prospective, cross-sectional study. Hospital setting. PARTICIPANTS: One hundred seventy-three subjects (85 glaucoma and 88 normal subjects). METHODS: One eye from each individual was selected randomly for RNFLT imaging by the spectral domain Cirrus OCT and HRT3. MAIN OUTCOME MEASURES: Global RNFL thickness and measurements at the four quadrants around the optic disc were analyzed and compared for differences, agreement of the categorical classification, diagnostic sensitivities and specificities and the area under the receiver operating characteristic curves (AUC). RESULTS: RNFL thickness as determined by HRT3 were significantly thicker than measurements done by Cirrus OCT (respectively in μm, 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 for RNFL thickness (within normal limits, borderline, or outside normal limits) ranged between poor to fair. CONCLUSIONS: RNFL thickness measurements by Cirrus OCT and HRT3 are strongly correlated but significantly different. The differences between paired RNFL measurements are substantial and proportional to the RNFL thickness. The normative diagnostic classification of the 2 technologies may not agree. The results preclude interchangeable use of these measurements in clinical practice.
Glaucoma Unit, Sydney Eye Hospital, Sydney, NSW, Australia; Department of Ophthalmology, Soroka University Medical Centre, Beer Sheva, Israel; Faculty of Health Sciences, Ben Gurion Univeristy of the Negev, Beer Sheva, Israel.
Full article6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
6.9.1.1 Confocal Scanning Laser Ophthalmoscopy (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.1 Laser scanning)