FIG. 1. A. The indocyanine green (ICG) molecule has biophysical properties that make it useful for visualizing the choroidal circulation. B, C and D. These properties make it possible to visualize choroidal neovessels beneath blood layers, exudates or RPE detachments (PEDs) by differentiating (in the latter case) between the hypofluorescent serous component and the hyperfluorescent vascular component. With FA, both the serous and the vascular component appear hyperfluorescent, and the limits of CNV may be masked as a result. A and B. Visualization of the choroidal circulation under thin blood layers. C. Hot spots visible in an area of exudation. D. PED with small CNV at the margin of the lesion.With FA, both the serous and the vascular component appear hyperfluorescent, while with ICGA only the vascular component of PED appears hyperfluorescent.