Fig. 4.
Geographic atrophy: (a) En face fundus image reconstructed from 3-D OCT data set, (b, c) reflectivity B-scan images, (d, e) Overlay of depolarizing structures within and outside the evaluation band shown in red and green color, respectively, and (f) retinal thickness map computed as axial distance between ILM and DOPUmin position. The DOPUmin position is usually located in the RPE. In the case of atrophy, this position was located in the choroid [green pixels in (d) and (e)]. (g) Map of overall number of depolarizing pixels per A-line. Zones of RPE atrophy are masked by choroidal depolarization. (h) Map displaying the thickness of the depolarizing layer inside the evaluation band. (j) Binary map of atrophic zones. The color map scales from 70 to 325 μm for (f) and from 0 to 39 pixels for (g) and (h).