The optic canal is 8–10 mm long and is located within the lesser wing of the sphenoid bone. This canal is separated from the superior orbital fissure by the bony optic strut. The optic nerve, ophthalmic artery, and sympathetic nerves pass through this canal. The orbital end of the canal is the optic foramen, which normally measures less than 6.5 mm in diameter in adults. Optic canal enlargement accompanies the expansion of the nerve, as seen with optic nerve gliomas. Narrowing of the canal occurs in disorders such as fibrous dysplasia. Blunt trauma may cause an optic canal fracture or shearing of the pial vessels in the foramen, resulting in optic nerve damage.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.