Corpus: Ophthalmic nerve
from ancient Greek: ὀφθαλμός ("ophthalmos") - eye
Synonyms: V1
1. Definition
The ophthalmic nerve is the first terminal branch of the trigeminal nerve (cranial nerve V), and carries general somatosensory fibers.
2. Course
After leaving the trigeminal ganglion, the ophthalmic nerve runs forward in the lateral wall of the cavernous sinus. Before entering the superior orbital fissure, it gives off a sensory meningeal branch and divides into four main branches after passing through the fissure:
- Tentorial branch
- Frontal nerve
- Lacrimal nerve
- Nasociliary nerve
3. Innervation
3.1. Tentorial branch
The tentorial branch, also known as the recurrent meningeal branch, carries sensory fibers to supply the dura mater in the area of the posterior cranial fossa.
3.2. Frontal nerve
The frontal nerve divides into two branches: The supratrochlear nerve runs to the medial corner of the eye and supplies the upper eyelid and the area around the medial corner of the eye. The supraorbital nerve passes through the supraorbital foramen and supplies sensation to the skin of the forehead.
3.3. Lacrimal nerve
The lacrimal nerve runs via the outer eye muscles to the lateral corner of the eye. It picks up fibers from the zygomatic nerve, which innervate the lacrimal gland. These are postganglionic parasympathetic fibers, connected in the pterygopalatine ganglion, and sympathetic fibers from the internal carotid plexus. The lacrimal nerve supplies the lateral corner of the eye and the lateral upper eyelid with its own fibers.
3.4. Nasociliary nerve
The nasociliary nerve runs via the optic nerve from the lateral to the medial corner of the eye. It carries fibers for the sensory supply of the eyeball, which run to the ciliary ganglion. It gives off the anterior and the posterior ethmoidal nerves, which supply the ethmoidal air cells, the sphenoidal sinus, and the nasal septum. The terminal branch of the nasociliary nerve supplies the skin on the bridge of the nose up to the tip of the nose.