Ophthalmic Nerve

Origin

The ophthalmic nerve originates at the trigeminal ganglion as one of three branches of the trigeminal nerve. It is the most superior and anterior of the branches.

The cell bodies of the neurons that make up the ophthalmic nerve are found in the trigeminal ganglion. They project to the main sensory nucleus of trigeminal nerve and the spinal nucleus of trigeminal nerve, both of which are located in the pons.

Course

The ophthalmic nerve emerges from the anterior portion of the trigeminal ganglion. It runs anteriorly, passing through the lateral portion of the cavernous sinus until it reaches the superior orbital fissure. Here it passes into the orbit. As it passes through or just proximal to the superior orbital fissure, the ophthalmic nerve divides into its three major branches (Norton, 2016).

Branches

The ophthalmic nerve gives rise to three major branches and one minor branch.

The minor branch is the tentorial branch, also called the recurrent meningeal branch of the ophthalmic nerve. It branches off the ophthalmic nerve within the cavernous sinus.

The major branches of the ophthalmic nerve are the nasociliary, frontal, and lacrimal nerves. These branches arise from the ophthalmic nerve either proximal to or as it passes through the superior orbital fissure.

Supplied Structures

The ophthalmic nerve conveys general sensation from portions of the skin and mucosal linings of the upper face, orbit, paranasal sinuses, and nasal cavity. Some branches of the ophthalmic nerve will pick up parasympathetic fibers from other sources, but the ophthalmic nerve itself does not have any parasympathetic axons.

The nasociliary nerve conveys sensation from the sphenoid sinus, the ethmoid air cells, portions of the nasal cavity, the apex of the external nose, and the eye. Sympathetic and parasympathetic fibers run with branches of the nasociliary nerve to the pupillary dilator and constrictor muscles, as well as the ciliary muscles.

The frontal nerve is most accurately considered the continuation of the ophthalmic nerve. It runs from the superior orbital fissure just deep to the periosteum and exiting the superior aspect of the orbit. It conveys sensation from the skin of the upper eyelid and scalp, frontal sinus, as well as the conjunctiva of the upper eyelid.

The lacrimal nerve is the smallest branch of the three and conveys sensation from the lacrimal gland, skin of the upper eyelid, and conjunctiva of the upper eyelid.

The tentorial branch of the ophthalmic nerve conveys sensation from a small portion of cranial dura, typically restricted to portions of the tentorium cerebelli and the falx cerebri (Norton, 2016).

List of Clinical Correlates

—Corneal reflex

References

Norton, N. S. (2016) Netter's Head and Neck Anatomy for Dentistry E-BookElsevier Health Sciences.