Retinal venous occlusion Central retinal vein occlusion 2019-07-06T21:10:20Z Central retinal vein occlusion is an occlusion of the main retinal vein posterior to the lamina cribrosa of the optic nerve and is typically caused by thrombosis. Central retinal vein occlusion may be associated with glaucoma or ocular hypertension. If the central retinal vein has two tributaries at the optic disc, hemiretinal vein occlusion may occur. It can cause cilioretinal arteriolar hypoperfusion.