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Abstract #6350 Published in IGR 3-2
Interobserver variability of optic disc variables measured by confocal scanning laser tomography
Iester M; Mikelberg FS; Courtright P; Burk ROW; Caprioli J; Jonas JB; Weinreb RN; Zangwill LMAmerican Journal of Ophthalmology 2001; 132: 57-62
PURPOSE: To assess the interobserver variation of confocal laser scanning tomographic measurements of the optic nerve head and to address the question of whether the addition of clinical optic disc photographs is helpful in outlining the optic disc margin and in reducing the observer-related variation of the measurements. PATIENTS AND METHODS: Optic disc variables for 16 eyes of 16 patients with glaucoma, generated by confocal laser scanning tomography (Heidelberg Retina Tomograph), were independently evaluated by four experienced glaucoma specialists, and the interobserver variability was calculated. A second separate review by the same observers included the use of clinical stereoscopic color optic nerve head photographs to aid definition of the optic disc margin. RESULTS: Optic disc parameters with the smallest interobservation variation were cup shape measure, maximum cup depth, height variation contour, and mean height contour. The intraobserver variation of these parameters did not increase when clinical optic disc slides were additionally available. parameters with the highest interobserver variation were volume below surface, volume below reference, volume above surface, and volume above reference. The observer variation of these optic disc parameters increased significantly for two of the four examiners when clinical optic disc slides were additionally available for outlining the optic disc margin. CONCLUSIONS: Confocal laser scanning tomography of the optic nerve head can be improved significantly if clinical optic disc photographs are additionally available to help in outlining the optic disc margin. Because interobserver variation in the tomographic optic disc measurements can be significant, even if experienced observers are involved, tomographic optic disc measurements may be centralized in reading centers in the case of multicenter studies.
Dr F.S. Mikelberg, Eye Care Centre, University of British Columbia, 2550 Willow Street, Vancouver, BC, V5Z 3N9, Canada. fsm@interchange.ubc.ca
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
6.9.1 Laser scanning (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)
