The ophthalmic artery (OA) is an artery of the head. It is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the ophthalmic artery supply all the structures in the orbit around the eye, as well as some structures in the nose, face, and meninges. Occlusion of the ophthalmic artery or its branches can produce sight-threatening conditions.
The ophthalmic artery emerges from the internal carotid artery. [1] This is usually just after the internal carotid artery emerges from the cavernous sinus. In some cases, the ophthalmic artery branches just before the internal carotid exits the cavernous sinus. The ophthalmic artery emerges along the medial side of the anterior clinoid process. It runs anteriorly, passing through the optic canal inferolaterally to the optic nerve. [1] It can also pass superiorly to the optic nerve in a minority of cases. [2] In the posterior third of the cone of the orbit, the ophthalmic artery turns sharply and medially to run along the medial wall of the orbit.
Because of the obvious importance of the ocular globe, branches of the ophthalmic artery often are subdivided into two groups: those that supply the eyeball (ocular group) and those that supply non-ocular orbital structures (orbital group). [3]
The orbital group, distributing vessels to the orbit and surrounding parts, includes:
The ocular group, distributing vessels to the eye and its muscles, includes:
The central retinal artery is the first, and one of the smaller branches of the ophthalmic artery and runs in the dura mater inferior to the optic nerve. About 12.5mm (0.5 inch) posterior to the globe, the central retinal artery turns superiorly and penetrates the optic nerve, continuing along the center of the optic nerve, entering the eye to supply the inner retinal layers.
The next branch of the ophthalmic artery is the lacrimal artery, one of the largest, arises just as the OA enters the orbit and runs along the superior edge of the lateral rectus muscle to supply the lacrimal gland, eyelids and conjunctiva.
The ophthalmic artery then turns medially, giving off 1 to 5 posterior ciliary arteries (PCA) that subsequently branch into the long and short posterior ciliary arteries (LPCA and SPCA respectively) which perforate the sclera posteriorly in the vicinity of the optic nerve and macula to supply the posterior uveal tract. In the past, anatomists made little distinction between the posterior ciliary arteries and the short and long posterior ciliary arteries often using the terms synonymously. However, recent work by Hayreh has shown that there is both an anatomic and clinically useful distinction. [4] The PCAs arise directly from the OA and are end arteries which is to say no PCA or any of its branches anastomose with any other artery. Consequently, sudden occlusion of any PCA will produce an infarct in the region of the choroid supplied by that particular PCA. Occlusion of a short or long PCA will produce a smaller choroidal infarct, within the larger area supplied by the specific parent PCA.
The ophthalmic artery continues medially the superior and inferior muscular branches arise either from the ophthalmic artery directly or a single trunk from the ophthalmic artery subsequently divides into superior and inferior branches to supply the extraocular muscles.
The supraorbital artery branches from the ophthalmic artery as it passes over the optic nerve. The supraorbital artery passes anteriorly along the medial border of the superior rectus and levator palpebrae and through the supraorbital foramen to supply muscles and skin of the forehead.
After reaching the medial wall of the orbit, the ophthalmic artery again turns anteriorly. The posterior ethmoidal artery enters the nose via the posterior ethmoidal canal and supplies the posterior ethmoidal sinuses and enters the skull to supply the meninges.
The OA continues anteriorly, giving off the anterior ethmoidal artery which enters the nose after traversing the anterior ethmoidal canal and supplies the anterior and middle ethmoidal sinuses, as well as the frontal sinus and also enters the cranium to supply the meninges.
The OA continues anteriorly to the trochlea, where the medial palpebral arteries (superior and inferior) arise and supply the eyelids.
The OA terminates in two branches, the supratrochlear (or frontal) artery and the dorsal nasal artery. Both exit the orbit medially to supply the forehead and scalp.
Branches of the ophthalmic artery supply:
Severe occlusion of the ophthalmic artery causes ocular ischemic syndrome. As with central retinal artery occlusions, ophthalmic artery occlusions may result from systemic cardiovascular diseases; however, a cherry-red spot is typically absent and the vision is usually worse. Amaurosis fugax is a temporary loss of vision that occurs in two conditions which cause a temporary reduction in ophthalmic artery pressure: orthostatic hypotension and positive acceleration. [5]
Even complete occlusion of the ophthalmic artery may possibly leave the eye without symptoms, probably because of circulatory anastomoses [6]
Articles related to anatomy include:
The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation. The oculomotor nerve is derived from the basal plate of the embryonic midbrain. Cranial nerves IV and VI also participate in control of eye movement.
The internal carotid artery is an artery in the neck which supplies the anterior circulation of the brain.
In anatomy, the orbit is the cavity or socket/hole of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is 30 millilitres, of which the eye occupies 6.5 ml. The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and duct, the eyelids, medial and lateral palpebral ligaments, cheek ligaments, the suspensory ligament, septum, ciliary ganglion and short ciliary nerves.
The medial rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the common tendinous ring, and inserts into the anteromedial surface of the eye. It is supplied by the inferior division of the oculomotor nerve (III). It rotates the eye medially (adduction).
The extraocular muscles, or extrinsic ocular muscles, are the seven extrinsic muscles of the eye in humans and other animals. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye. The other muscle, the levator palpebrae superioris, controls eyelid elevation. The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction.
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
The ophthalmic nerve (CN V1) is a sensory nerve of the head. It is one of three divisions of the trigeminal nerve (CN V), a cranial nerve. It has three major branches which provide sensory innervation to the eye, and the skin of the upper face and anterior scalp, as well as other structures of the head.
The nasociliary nerve is a branch of the ophthalmic nerve (CN V1) (which is in turn a branch of the trigeminal nerve (CN V)). It is intermediate in size between the other two branches of the ophthalmic nerve, the frontal nerve and lacrimal nerve.
The superior ophthalmic vein is a vein of the orbit that drains venous blood from structures of the upper orbit. It is formed by the union of the angular vein, and supraorbital vein. It passes backwards within the orbit alongside the ophthalmic artery, then exits the orbit through the superior orbital fissure to drain into the cavernous sinus.
The anterior ethmoidal artery is a branch of the ophthalmic artery in the orbit. It exits the orbit through the anterior ethmoidal foramen alongside the anterior ethmoidal nerve. It contributes blood supply to the ethmoid sinuses, frontal sinuses, the dura mater, lateral nasal wall, and nasal septum. It issues a meningeal branch, and nasal branches.
The posterior ethmoidal artery is an artery of the head which arises from the ophthalmic artery to supply the posterior ethmoidal air cells, and the meninges. It is smaller than the anterior ethmoidal artery.
The supraorbital artery is a branch of the ophthalmic artery. It passes anteriorly within the orbit to exit the orbit through the supraorbital foramen or notch alongside the supraorbital nerve, splitting into two terminal branches which go on to form anastomoses with arteries of the head.
The long posterior ciliary arteries are arteries of the orbit. There are long posterior ciliary arteries two on each side of the body. They are branches of the ophthalmic artery. They pass forward within the eye to reach the ciliary body where they ramify and anastomose with the anterior ciliary arteries, thus forming the major arterial circle of the iris.The long posterior ciliary arteries contribute arterial supply to the choroid, ciliary body, and iris.
The short posterior ciliary arteries are a number of branches of the ophthalmic artery. They pass forward with the optic nerve to reach the eyeball, piercing the sclera around the entry of the optic nerve into the eyeball.
The anterior ciliary arteries are seven arteries in each eye-socket that arise from muscular branches of the ophthalmic artery and supply the conjunctiva, sclera, rectus muscles, and the ciliary body. The arteries end by anastomosing with branches of the long posterior ciliary arteries to form the circulus arteriosus major.
In anatomy, arterial tree is used to refer to all arteries and/or the branching pattern of the arteries. This article regards the human arterial tree. Starting from the aorta:
The central retinal vein is a vein that drains the retina of the eye. It travels backwards through the centre of the optic nerve accompanied by the central retinal artery before exiting the optic nerve together with the central retinal artery to drain into either the superior ophthalmic vein or the cavernous sinus.
The following outline is provided as an overview of and topical guide to human anatomy: