This 74YO female has large optic nerve collaterals from an old non-ischemic central retinal vein occlusion. Vision was 20/30.
Learning Points:
Collateral vessels are dilated, pre-existing vessels that bypass an occlusion. These are most commonly seen in the posterior pole, following retinal venous occlusions, often on the optic disc.
In collateral vessels, the endothelial tight junctions are intact, so they don’t leak angiographically. This helps differentiate them from neovascularization, which does leak.
