Three-dimensional reconstruction of optic nerve head from stereo fundus images and its quantitative estimation

It is important for diagnosis of glaucoma to grasp 3-D structure of an optic nerve head (ONH). The quantitative 3-D reconstruction of the ONH is required for the diagnosis. We propose a technique to obtain the depth value from stereo image pair of a retinal fundus for the 3-D reconstruction of the ONH. Our technique mainly consists of four steps: (1) cutout of the ONH region from the fundus images, (2) registration of the stereo pair, (3) disparity detection, and (4) depth calculation. For quantitative estimation of the depth value measured by using this method, the depth value was compared with the measurement results determined from the Heidelberg Retina Tomograph (HRT), which is a confocal laser-scanning microscope. As a result, the depth value of the ONH obtained using the stereo retinal image pair was in accordance with that obtained using the HRT (r=0.91). These results indicate that the stereo fundus images could be useful for assessing the depth value of the ONH for the diagnosis of glaucoma.