Optic Cup Slope as a Numeric Representative of Glaucomatous Cupping. |
Sang Il Ahn, Jee Ho Chang |
Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea. jhchang@schmc.ac.kr |
녹내장성 시신경유두함몰 지표로서의 기울기 |
안상일⋅장지호 |
Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea |
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Abstract |
PURPOSE To objectively define the degree of cupping, the authors extracted 3-dimensional slope surface maps from Cirrus HDTM-OCT data and assessed their differentiating characteristics between normal subjects and glaucomatous patients. METHODS: One eye from each of 40 normal subjects and 1 eye from each of 39 patients with glaucoma were examined using automated visual field perimetry and Cirrus HDTM-OCT. The Optic Disc Cube 200 x 200 protocol was performed. The individual OCT data were reconstructed as the 3-dimensional surface maps of the optic disc cup and the slope of each contour was calculated using custom-developed software. Several disc cup slope parameters were derived. The parameters measuring the internal features of the optic disc cup were calculated and compared between groups. RESULTS: Sum of cup slope, sum of thresholded cup slope, and sum of thresholded cup slope / thresholded cup area parameters were differentiating factors between the normal and glaucoma groups (p < 0.05). The area under the receiver operating characteristic curve (AUROC) value of the slope parameters ranged from 0.718 to 0.753. The sum of thresholded cup slope / thresholded cup area parameter was well correlated with visual field mean deviation (r = -0.250, p = 0.028). CONCLUSIONS: The optic disc cup slope parameter obtained with OCT may be a useful parameter for representing glaucomatous cupping. |
Key Words:
Cup slope;Disc cup;Glaucoma;OCT |
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