It travels backwards through the centre of the optic nerve accompanied by the central retinal artery before exiting the optic nerve together with the central retinal artery to drain into either the superior ophthalmic vein or the cavernous sinus.
[1] The central retinal vein runs through the centre of the optic nerve (alongside the central retinal artery) surrounded by a fibrous connective tissue envelope.
[2] It leaves the optic nerve 10 mm from the eyeball[citation needed] along with the central retinal artery, also exiting the meningeal envelope of the optic nerve.
[1] The central retinal vein varies between individuals.
As the fluid surrounding the optic nerve within its meningeal envelope is contiguous with the cerebrospinal fluid of the central nervous system, increased intracranial pressure can cause compression of the central retinal vein where it emerges from the optic nerve (the accompanying artery is meanwhile less susceptible to compression due to its thicker arterial wall), with the resulting venous congestion causing oedema of the optic nerve (papilledema).