Figure 5
A functional end-arterial model of the choroidal circulation. Red and gray vascular channels represent perfused and non-perfused status, respectively. (a) When a terminal arteriole is obstructed, the choriocapillaris lobule becomes ischemic because the blood is drained through the venous channel in the periphery of the lobule. (b) A sector becomes ischemic when the posterior ciliary artery is occluded, as there is no arteriolar anastomosis among the other sectors. (c) When triolein embolus flows down to a small arteriole, perfusion of the choriocapillaris is restored owing to the extensive arteriolar anastomosis within the sector.
