Orbital foramen

Orbital foramen is a term used in anatomy to refer to any of the openings (foramina) in the orbit, the bony cavity in the skull that houses the eye. These foramina serve as passageways for nerves, arteries, and veins that supply the structures within the orbit.

Types of Orbital Foramina

There are several types of orbital foramina, each with its own specific function and structures passing through it.

Optic Canal

The optic canal is a foramen located at the back of the orbit. It allows the passage of the optic nerve, which transmits visual information from the retina to the brain, and the ophthalmic artery, which supplies blood to the eye and surrounding structures.

Superior Orbital Fissure

The superior orbital fissure is a large, irregularly shaped foramen located between the lesser and greater wings of the sphenoid bone. It transmits several important structures, including the oculomotor, trochlear, and abducens nerves, which control eye movements, and the ophthalmic division of the trigeminal nerve, which provides sensation to the forehead and upper eyelid.

Inferior Orbital Fissure

The inferior orbital fissure is a foramen located between the maxilla and the greater wing of the sphenoid bone. It allows the passage of the infraorbital nerve, a branch of the maxillary division of the trigeminal nerve, which provides sensation to the lower eyelid, cheek, and upper lip. It also transmits the infraorbital artery and vein, which supply blood to these same areas.

Nasolacrimal Canal

The nasolacrimal canal is a small foramen located at the front of the orbit. It contains the nasolacrimal duct, which drains tears from the eye into the nasal cavity.

Clinical Significance

Due to their role as passageways for important structures, the orbital foramina can be involved in various medical conditions. For example, fractures involving the orbit can damage the structures passing through the foramina, leading to vision loss or impaired eye movements. In addition, tumors or other masses in the orbit can compress these structures, causing similar symptoms.