Anatomy, Head and Neck, Eye Arteries

The branches of the ophthalmic artery comprise the entire arterial supply to the eye. Most commonly the ophthalmic artery branches off of the internal carotid artery, distal to the cavernous sinus, then travels through the optic canal. The ophthalmic artery has multiple branches which separate into two categories: orbital branches and optical branches. The orbital arteries include the ciliary arteries, central retinal artery, and muscular arteries.[1]: Long Posterior Ciliary Arteries: The long posterior ciliary arteries (1 to 2) travel near the optic nerve and pierce the posterior sclera to supply the choroid and ciliary muscle before joining the major arterial circle of the iris.[2] The major arterial circle of the iris distributes branches to the iris and ciliary body. Short Posterior Ciliary Arteries: The number of short posterior ciliary arteries vary per individual, often ranging between 6 to 12 arteries that branch off the ophthalmic artery as it crosses the optic nerve medially. These arteries supply the ciliary processes and optic disk. The arterioles branching from the posterior ciliary arteries supply the choroid. The perpendicular terminal arterioles supply choriocapillaris, the blood supply to Bruch's membrane and outer retina.[3]. Anterior Ciliary Arteries: There are seven anterior ciliary arteries that branch from the muscular arteries and run with the extraocular muscles. The anterior ciliary arteries supply the rectus muscles, conjunctiva, and sclera before joining the long posterior ciliary arteries to form the major arterial circle of the iris.[2] Each rectus muscle receives its vascular supply from two anterior ciliary arteries, except the lateral rectus which receives blood supply from only one anterior ciliary artery. Central Retinal Artery: It is the first branch of the ophthalmic artery. It is a terminal branch supplying the inner layer of the retina, and its occlusion can cause sudden visual loss. It travels inferiorly and within the optic nerve sheath to supply the inner two-thirds of the retina. The artery further divides into superior and inferior arcades, which form the blood-retina barrier. Muscular branches: The two muscular branches of the ophthalmic artery that supply extraocular muscles include the medial and lateral muscular branches. The medial artery being larger than the lateral muscular branch.