Central Retinal Vein Occlusion - Disc Collaterals

This is the optic disc appearance of a woman who had suffered a central retinal vein occlusion of the right eye six years previously. The identified veins (black arrows) are dilated, pre-existing channels connecting retinal venous return to choroidal veins. They can also occur with many other conditions including longstanding open angle glaucoma and optic nerve sheath meningioma.