ABSTRACT
Anatomy The orbit is composed of seven bones: the zygoma, sphenoid, frontal, ethmoid,
maxilla, lacrimal and palatine bones (Fig. 37.1). Residing inside the bony orbit are two fissures, the superior and inferior orbital fissures. Through the superior orbital fissure (SOF) pass the occulomotor (CN III), trochlear (CN IV), ophthalmic divi sion of the trigeminal (CN VI) and the abducens (CN VI) nerves. It is located in a superolateral position relative to the optic foramen and divides the greater and lesser wings o f the sphenoid bone. The inferior orbital fissure (IOF) resides between the lesser wing of the sphenoid and the maxilla and is oriented in an inferolateral direc tion. Traversing the IOF are the second division of the trigeminal nerve (CN V2), branches off of the sphenopalatine ganglion and the inferior ophthalmic vein.
