Anatomy: Anatomy of the Ocular Vasculatures

The eye is an incredible assembly of unique types of tissues, each of which has its own requirements in terms of blood supply. The eye contains avascular tissues that must have nutrition like cornea and lens to richly vascularized tissue like iris, retina, and choroid. The sources of blood for the eye are the retinal artery and the posterior and anterior ciliary arteries derived from the ophthalmic artery. The ophthalmic artery is the most often stenosed vessel from the internal carotid artery because of its right-angle branching from the carotid. Eighty percent of the ocular blood goes to the uveal tract and 20% to the retina. The anterior ciliary arteries enter the globe from the rectus muscles to provide blood to the limbal, conjunctival, and the scleral vasculatures (Fig. 1.1). The posterior ciliary arteries supply the choroid.