Figure 8.
Imaging of the capillary lamina of the choroid (choriocapillaris) and its morphometry
(A) STOC-T angiography map (binarized after Frangi Hessian filtering) of the 10 μm-thick layer located next to the RPE, showing the capillary network image; the ROI areas 1–3 represent individual tiles of the mosaic.
(B) SEM image showing the morphology of the choriocapillaris (adapted from54).
(C) Magnified sections of the STOC-T angiography maps (non-binarized version) from the areas highlighted in panel a.; green arrows indicate a small vascular sub-system with a specific morphology recurring in each ROI; ROI 2 corresponds to the area located directly in the Foveal zone as indicated with a red dashed circle.
(D) Contrast enhanced STOC-T angiography images (binarized) obtained by using the Frangi-Hessian algorithm.
(E) Quantitative analysis of the choriocapillary vascular system by automatic detection of loops and junctions; the graphs show the results of counting loops and density of junctions dJ for the choriocapillaris and three projections from Sattler’s layer, reproduced in Figure 6; NDC - normalized capillary density, d – mean capillary size, dL# - local capillary density, Rmax – maximum radius of loop present in ROI; a significant difference in Rmax was observed between the area of the fovea centralis and the area near the optic nerve disc.