Figure 5.

Adaptive optics OCT cross-sectional and en face images extracted from the photoreceptor-RPE complex of a 48–year-old subject (S5) at eight retinal eccentricities. (a) Clinical OCT is shown for comparison, a Spectralis OCT B-scan that bisects the fovea along horizontal meridian of the same subject. IS/OS and COST bands are distinct, but RPE and ROST bands are undifferentiated. (b) Adaptive optics OCT averaged B-scans and corresponding A-scan profiles (yellow trace) of volumes reveal distinct reflectance bands within the complex labeled IS/OS, COST, ROST, and RPE. Note the increase in ROST peak with retinal eccentricity. (c) En face projection views of single frames are shown with depth color coded; that is, IS/OS + COST (yellow) and ROST (blue) layers. The blue punctate reflections are consistent with individual rods that surround cones (yellow), which themselves become increasingly larger outside the fovea and displace adjacent rods. White denotes overlap of cone and rod reflections, which, while infrequent, occurs at retinal locations closer to fovea. This apparent overlap is likely attributable to limitations in the AO-OCT resolution and segmentation of COST and ROST, cell end tips that get increasingly narrow and close together in the fovea.