Fig. 24. Choroidal functional vascular unit as proposed by Fryczkowski. A. Anatomical choroidal lobule based on the vascular casts and SEM study. Note centripetal arrangement of the capillaries. Collecting venule (long, thin arrow) originated from the center of the lobule forming 90° angle with choriocapillaries. B. Functional choroidal lobule outlined by the pressure gradient based on the fluorescein and ICG angiographic study. Centrifugal arrangement of the capillaries originated from arteriole. Feeding arteriole reaches the choriocapillaries at 90° angle. (Courtesy of A. Fryczkowski, MD)