Superior and inferior orbital fissures: Neurovasculature (English)

The superior orbital fissure is located superolateral to the optic canal and positioned between the lesser and greater wings of the sphenoid bone. The common tendinous ring is situated along the anteroinferior aspect of the superior orbital fissure. Several nerves and veins pass through the superior orbital fissure with some also extending within the common tendinous ring. From superior to inferior, the contents of the superior orbital fissure include the lacrimal nerve, frontal nerve, superior ophthalmic vein, trochlear nerve (CN IV), the superior branch of the oculomotor nerve (CN III), nasociliary nerve, abducens nerve (CN VI), the inferior branch of the oculomotor nerve (CN III) and the superior branch of the inferior ophthalmic vein. The inferior orbital fissure is located between the sphenoid bone and maxilla and lies inferolateral to the optic canal and inferior to the superior orbital fissure. It opens into the posterolateral aspect of the orbital floor and allows the passage of several neurovascular structures. Contents of the inferior orbital fissure include the infraorbital nerve, zygomatic nerve, inferior branch of the inferior ophthalmic vein, infraorbital artery and the orbital branches of the pterygopalatine ganglion.