Choroid changes in vortex vein-occluded monkeys

Aim: To determine acute and chronic choroidal vascular changes after vortex vein occlusion in monkeys.

Methods: One or two temporal vortex veins were occluded in 8 cynomolgus monkeys. Fluorescein angiography (FA), indocyanine green angiogram (ICGA), and enhanced-depth imaging optical coherence tomography (EDI-OCT) were performed preoperatively and at 1d, 1, 4, 8 and 12wk after occlusion. EDI-OCT images were binarized to calculate the choroid vascular index (CVI).

Results: ICGA showed delayed filling of choroidal arteries in occluded quadrants in eyes with two occluded temporal vortex veins within 1wk. The thickness of the superotemporal choroid increased 1d and 4wk after occlusion, the thickness of the superonasal and inferonasal choroid increased 12wk after occlusion, and the CVI of the superonasal quadrant increased 8wk after occlusion in eyes with 2 occluded vortex veins.

Conclusion: Occlusion of two vortex veins leads to hemodynamic and structural changes in choroidal layers in the acute phase, while autoregulation may play the main role in the long term. Occlusion of one vortex vein has little influence on the hemodynamic and structural status of the choroid.