Retinal Artery Occlusions

The central retinal artery (CRA) is a branch of the ophthalmic artery, which is the first branch of the internal carotid artery. The CRA supplies blood to the surface of the optic disc. From here it divides into two main branches (superior and inferior); these then further divide into temporal and nasal branches, which supply blood to the four quadrants of the retina. The outer retina is supplied by the choriocapillaries of the choroid that branches off the ciliary artery. Both the CRA and the ciliary artery must be functioning to maintain retinal function, as both CRA and ciliary artery originate from the OA. One important variation is the presence of a cilioretinal artery. This artery, thought to be present in 1530% of people, supplies the macular retina to a varying degree and may help preserve some vision after CRAO. The cilioretinal artery is seen ophthalmoscopically as a single vessel emerging from the edge of the optic disc, most commonly towards the macula.