advertisement
Abstract #18128 Published in IGR 9-2
A comparison of structural measurements using 2 Stratus optical coherence tomography instruments
Sehi M; Guaqueta DC; Feuer WJ; Greenfield DSJournal of Glaucoma 2007; 16: 287-292
PURPOSE: To compare measures of peripapillary retinal nerve fiber layer (RNFL) thickness, optic disc topography, and central foveal thickness generated using 2 different Stratus optical coherence tomography (OCT) instruments. METHODS: Ten normal subjects and 10 glaucoma subjects were included. One randomly selected eye per subject was scanned consecutively using a fast RNFL thickness protocol, fast macular thickness map, and fast optic disc protocol by two experienced operators on two instruments. The order of the machines and operators were randomized. The output power of each machine was measured using an optical power meter. For each OCT measurement 2 factor fixed effects analyses of variance were performed and a restricted maximum likelihood variance component analysis of the proportion of variance due to subject, operator, and machine was calculated. RESULTS: Significant differences (P≤0.003) between OCT instruments were observed in average, superior, and inferior RNFL thickness and central foveal thickness values among normal eyes; and average and superior RNFL thickness and cup/disc area ratio values among glaucomatous eyes. Overall, the intermachine variability (0.0% to 16.4%) was larger than the interoperator variability (0.0% to 2.4%) for all OCT measurements. In the glaucoma group the variability due to machine differences was 2.6 μm for the average RNFL thickness, 5.7 μm for the superior RNFL thickness, 0 μm for the inferior RNFL thickness, 0.03 μm for the cup/disc area ratio, 0.01 μm for the cup/disc vertical ratio, and 2.8 μm for the average foveal thickness. CONCLUSIONS: Measurements of RNFL thickness, optic disc topography, and central foveal thickness significantly differ between OCT instruments.
Dr. M. Sehi, Department of Ophthalmology, University of Miami Miller School of Medicine, Bascom Palmer Eye Institute, Palm Beach Gardens, FL 33418, USA. msehi@med.miami.edu
Classification:
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
