ABSTRACT
The visual pathway runs from the retina to the occipital cortex and its blood supply is from the internal carotid and the vertebro-basilar arterial systems. The two systems anastomose in the circle of Willis at the base of the brain. Starting anteriorly, the blood supply to the visual pathway is described below:
retina:
– inner third by the central retinal artery
– outer two-thirds by the long and short posterior ciliary arteries via the choroidal circulation
– outer plexiform layer is at the junction between these two supplies
optic nerve:
– intraocular portion: short posterior ciliary arteries from the circle of Zinn
– orbital portion: via the pial plexus from the ophthalmic artery. The central retinal artery also contributes
– intracanalicular portion: via pial plexus from recurrent branches of the ophthalmic artery
– intracranial portion: via pial plexus from the ophthalmic and superior hypophyseal arteries
optic chiasma:
– from the pial plexus, here supplied by branches of the internal carotid artery, superior hypophyseal artery and anterior and posterior communicating arteries
optic tract:
– from the pial plexus, here supplied by branches of the anterior choroidal and posterior communicating arteries
lateral geniculate nucleus:
– from the pial plexus, here supplied by the anterior choroidal branch of the middle cerebral artery, the thalamogeniculate branch of the posterior cerebral artery and the lateral choroidal artery
optic radiation:
– anteriorly by the anterior choroidal and middle cerebral arteries
– posteriorly by the middle and posterior cerebral arteries
visual cortex:
– posterior and middle cerebral arteries, the latter anastomosing with the macular area.
