Ofthalmic nerve

OPHTHALMIC NERVE

Mónica Delgado Castillo

◦The ophthalmic nerve is one of the three branches of the trigeminal nerve. The ophthalmic nerve carries only sensory fibers

◦The ophthalmic nerve supplies branches to the cornea, ciliary body, and iris; to thelacrimal gland and conjunctiva; to the part of the mucous membrane of the nasal cavity; and to the skin of the eyelids, eyebrow, forehead and  nose.

◦It is the smallest of the three divisions of the trigeminal, and arises from the upper part of the trigeminal ganglion as a short, flattened band, about 2.5 cm. long, which passes forward along the lateral wall of the cavernous sinus, below the oculomotor and trochlear nerves.

Damage to the ophthalmic nerve may occur as the result of a blocked blood supply caused by high blood pressure or diabetes, or inflammationof the arteries. Inflammation of theophthalmic nerve itself, called optic neuritis, if often caused by MS; and papilledema, or swelling of the nerve, is often brought on by head trauma, meningitis or a brain abscess or tumor.

◦if the nerve is damaged before the optic chiasm, the sight in only one eye will be affected. If the optic chiasm itself is damaged, peripheral vision in both eyes will likely be lost. Problems farther along one side of the nerve, nearer to the brain, will result in the opposite side of the visual field in each eye being lost.

Ophthalmic migraines.- are a little known form of migraine. Ophthalmic or ocular migraines are sometimes called silent migraines, because they can occur with or without a headache being present. They are characterized by a visual disturbance that occurs in one eye. Many ophthalmic migraineurs describe the migraine as if they are peering through a cracked glass window.

◦Tolosa–Hunt syndrome .- is a rare disorder characterized by severe and unilateral headaches with extraocular palsies, and pain around the sides and back of the eye, along with weakness and paralysis (ophthalmoplegia) of certain eye muscles.

◦affected individuals may experience paralysis of various facial nerves and drooping of the upper eyelid ( ptosis ). Occasionally the patient may present with a feeling of protrusion of one or both eyeballs ( exophthalmos ).