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Abstract #6649 Published in IGR 4-1
The Ocular Hypertension Treatment Study: reproducibility of cup/disc ratio measurements over time at an optic disc reading center
Feuer WJ; Parrish RK; Schiffman JC; Anderson DR; Budenz DL; Wells MC; Hess DJ; Kass MA; Gordon MOAmerican Journal of Ophthalmology 2002; 133: 19-28
PURPOSE: To determine the reproducibility over time of visual estimates of the horizontal cup/disc ratio by trained technicians from optic disc stereophotographs. METHODS: Baseline optic disc stereophotographs are graded at entry and regraded annually in a masked fashion. The 1636 participants in the Ocular Hypertension Treatment Study (OHTS) undergo stereoscopic optic disc photography at study entry and annually thereafter. Stereophotographs are graded independently by two technicians at the Optic Disc Reading Center. If the readers' estimates of horizontal cup/disc ratio differ by more than 0.2 disc diameters (DD), they attempt to reach a consensus; if they cannot, the horizontal cup/disc ratio is adjudicated by a glaucoma specialist. RESULTS: The percent of regradings differing by 0.2 DD or more from the estimate of horizontal cup/disc ratio made at entry was 4%, 6%, and 7%, respectively at years 1, 2, and 3. The percent differing by more than 0.2 DD was 1% or less at all years. Intraclass correlation coefficients were 0.93, 0.92, and 0.92, respectively. Estimates of horizontal cup/disc ratio from sequential full-frame photographs and simultaneous split-frame photographs appeared comparable and equally reproducible. Gradings by technicians were comparable to gradings by glaucoma specialists. CONCLUSIONS: High reproducibility between repeated gradings of baseline horizontal cup/disc ratio was achieved by trained technicians adhering to a rigorous protocol. Horizontal cup/disc ratio measurements in OHTS are sufficiently reproducible to provide information about the relationship of cup/disc ratio to the prognosis of individuals with ocular hypertension.
Dr. W.J. Feuer, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida 33136, USA
Classification:
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
6.8.2 Posterior segment (Part of: 6 Clinical examination methods > 6.8 Photography)