The ophthalmic artery is responsible for distributing oxygenated blood into the meninges, orbital structures and the facial area. It originates at the internal carotid artery distal and branches off into smaller arteries, such as the retinal, lacrimal, supraorbital and the ethmoidal arteries. An obstruction within the ophthalmic artery can result in damage to the retina and might cause sudden and severe vision loss.
The large arteries of the head and neck are known as the internal carotid arteries, from which the ophthalmic artery emerges. It is the first branch that comes off of the internal carotid artery, either just before or, in most cases, right after it leaves the cavernous sinus, which is situated at the base of the skull. The ophthalmic artery aids in supplying blood to the orbital structures such as the eyes, eyelids and extraocular muscles; the meninges, which are the membranes of the brain and spinal cord; and the nose and facial area.
The first artery that branches off from the ophthalmic artery is the central retinal artery, which travels within a fibrous membrane just below the optic nerve and supplies the retina with blood. Next are the posterior ciliary arteries, which branch off to supply the choroid with blood, and the lacrimal artery, which travels along the lateral rectus muscle to supply the mucous membrane that covers the sclera. The lacrimal artery also distributes blood to the eyelids and lacrimal gland, which is responsible for producing tears.
Other arteries that branch off from the ophthalmic artery are the posterior and anterior ethmoidal arteries. The posterior ethmoidal artery supplies blood to the posterior ethmoidal sinuses as it branches into the nose through the posterior ethmoidal canal, and the anterior ethmoidal artery supplies the anterior and middle ethmoidal sinuses. Both of these arteries are also responsible for supplying blood to the meninges. The supraorbital artery distributes blood to the frontal sinus, to the scalp and to the muscles and skin on the forehead.
Any kind of obstruction, such as a blood clot, that blocks or reduces blood flow in the ophthalmic artery can affect one's eyesight. Depending on how severe the obstruction, it can result in blurred vision or a temporary or permanent loss of vision. A fluorescein angiography, which is an X-ray of the bloodstream, can help spot an obstruction before it causes serious damage. During this process, a solution of sodium fluorescein is injected into the blood and is followed as it makes its way to the retina to determine whether there is an obstruction.