Blood supply to the retina

The retina is one of the most metabolically active tissues in the body, consuming oxygen more rapidly than the brain.¹ With such a high oxygen demand, the retina must have an extensive vascular network to maintain functionality.

The human retina is supplied by two sources: the central retinal artery (CRA) and the choroidal blood vessels, both of which originate from the ophthalmic artery. The inner retina is supplied by the CRA, which receives 20-30% of the total ocular blood flow and enters the eye at the optic nerve head where it divides into two major branches. These branches in turn divide into arterioles (superior, inferior, nasal and temporal), which extend away from the optic disc to supply separate areas of the retina (figure 1).