The uveal circulation consists of arteries entering the globe outside the optic nerve, these supply the uvea and outer and middle layers of the retina. The arteries of the uveal circulation, supplying the uvea and outer and middle layers of the retina, are branches of the ophthalmic artery and enter the eyeball without passing with the optic nerve.
Fluorescein angiography during the choroidal phase of perfusion has been used to study the origin of blood vessels comprising neovascular tissue of the optic disc. These newly formed vessels were shown to derive their blood supply primarily from the uveal circulation rather than from the retinal circulation. This is related to the observation that many normal disc blood vessels originate from the choroidal or posterior ciliary circulation.