Evaluation of optical coherence tomography findings in age-related macular degeneration: a reproducibility study of two independent reading centres
- Markus Ritter1,
- Julee Elledge2,
- Christian Simader1,
- Gabor G Deak1,
- Thomas Benesch3,
- Barbara A Blodi2,
- Ursula M Schmidt-Erfurth1
- 1Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
- 2Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, USA
- 3Department of Medical Statistics, Medical University of Vienna, Vienna, Austria
- Correspondence to Ursula M Schmidt-Erfurth, Department of Ophthalmology, Medical University of Vienna, Vienna, Austria;
- Accepted 18 April 2010
- Published Online First 30 August 2010
Background/aims To determine the reproducibility among readers of two independent certified centres, the Vienna Reading Center (VRC) and the University of Wisconsin-Madison Reading Center (UW-FPRC) for optical coherence tomography (OCT) images in age-related macular degeneration (AMD).
Methods Fast macular thickness scans and 6 mm cross hair scans were obtained from 100 eyes with all subtypes of AMD using Stratus OCT. Consensus readings were performed by two certified OCT readers of each reading center using their grading protocol. Common variables of both grading protocols, such as presence of cystoid spaces, subretinal fluid, vitreomacular traction and retinal pigment epithelial detachment, were compared using κ statistics. In addition, the intraclass correlation coefficient (ICC) was calculated for centre point thickness (CPT) of values re-measured manually in the presence of alignment errors.
Results The reproducibility was dependent on the variable measured with a κ value of 0.81 for the presence of cystoid spaces, 0.78 for the presence of subretinal fluid and 0.795 for the presence of vitreomacular traction. The lowest reproducibility was found for the presence of retinal pigment epithelial detachment with a κ value of 0.51. The CPT was re-measured in 29 out of 100 scans at both sites with an ICC of the re-measured thicknesses of 0.92.
Conclusion OCT scan data are crucial in monitoring treatment efficacy in AMD clinical trials. For comparison of results obtained by different reading centers, the inter-reading center reproducibility is essential. Although the reproducibility is generally high, the reliability depends on the selected morphological parameters.
Competing interests None.
Ethics approval This study was conducted with the approval of the Medical University of Vienna, Austria, and Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, USA.
Provenance and peer review Not commissioned; externally peer reviewed.
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