Figure 2.

In SD-OCT, a point source is scanned over the retina, acquiring one axial scan (A-scan) per retinal location. If the point source is scanned in a line across the retina, a 2D, cross-sectional image of the retina (B-scan) is created. If the point source is raster scanned, in two dimensions, a 3D, volumetric image may be generated. From the latter, areal (or en face) projections of the retinal layers at specific depths (C-scans) may be extracted. C-scans from the depths of bands 2 and 3 are shown (right). Both reveal regular mosaics of the overlapping bright spots²⁴ whose spacing agrees with histologic measurements of cone photoreceptors.⁷⁸ At both layers, reflected light appears to be confined, laterally, to the interior of the cell.