The six-stage Frisén scale is a qualitative and subjective method for assessing papilledema (optic disc swelling due to raised intracranial pressure) using fundus photographs. The recent introduction of spectral-domain optical coherence tomography (SD-OCT) presents a promising alternative to enable the 3-D quantitative estimation of papilledema. In this work, we propose an automated region-based volumetric estimation of the degree of papilledema from SD-OCT. After using a custom graph-based approach to segment the surfaces of the swollen optic nerve head, the volumes of the nasal, superior, temporal, and inferior regions are computed. Using a dataset of 70 SD-OCT optic-nerve-head (ONH) SD-OCT scans the Spearman rank correlation coefficients between expert-defined Frisén scale grades and the total retinal (TR) volume, nasal, superior, temporal, inferior regional volumes were 0.737, 0.752, 0.747, 0.770 and 0.758, respectively. Also, a fuzzy k-nearest-neighbor (k-NN) algorithm was used to predict Frisén scale grades (in a leave-one-subject-out fashion). Using multiple features rather than just the TR volume made the resulting mean Frisén grade difference (MGD) between the expert-defined grades 0.386 (down from 0.629) and prediction accuracy 64.29% (up from 41.43%).

Date Published: 29 March 2013
PDF: 8 pages
Proc. SPIE 8672, Medical Imaging 2013: Biomedical Applications in Molecular, Structural, and Functional Imaging, 867214 (29 March 2013); doi: 10.1117/12.2007001

Published in SPIE Proceedings Vol. 8672:
Medical Imaging 2013: Biomedical Applications in Molecular, Structural, and Functional Imaging
John B. Weaver; Robert C. Molthen, Editor(s)