Segmentation of the nerve fiber layer (NFL), ganglion cell layer (GCL) and combined layer of the outer segment (OS) and retinal pigment epithelium (RPE) from macular and peripapillary spectral-domain optical coherence tomography volumes. A, Flattened and cropped B-scan image of the macular spectral-domain optical coherence tomography volume. B, Image A overlaid with the layer segmentation results. C, Three-dimensional rendering of the surfaces segmented in B. D, Flattened and cropped B-scan image of the peripapillary spectral-domain optical coherence tomography volume. E, Image D overlaid with the layer segmentation results. F, Three-dimensional rendering of the surfaces segmented in image E. N indicates nasal; RPE*, RPE complex; and T, temporal