Isolated superior orbital fissure syndrome resulting from gunshot wound to the head.

A 41-year-old man, shot in the face with a handgun, showed left V1 paraesthesia, limited light perception in the left eye, and complete ophthalmoplegia with proptosis and mydriasis. Unenhanced computed tomography (CT) scan showed multiple comminuted fractures of the left orbit, with the bullet lodged near the superior orbital fissure (Fig 1A). Cranial CT angiogram (Fig 1B) and cerebral angiogram (Fig 2) showed dilation of the left superior orbital vein and an isolated segmental 50% narrowing of the internal carotid artery without intrinsic abnormality. Surgical exploration was declined. Despite treatment with high-dose steroids, severe ophthalmoplegia remained, although vision rapidly improved. The complexity of the orbital apex is related to the confluence of crucial neurovascular structures as they transition from the cranium to the orbit and face. The ophthalmic artery and cranial nerves (CN) II, III, IV, V1, and VI transition from the middle cranial fossa to the orbital apex via the superior orbital fissure. Medially, the superior orbital fissure is enclosed by the annulus of Zinn, from which the 4 extraocular recti muscles arise. The infraorbital artery and vein and CN V2 transition via the infraorbital foramen. Superior orbital fissure syndrome (SOFS) reflects injury to neurovascular structures traversing the superior orbital fissure manifest by fixed and dilated pupil (parasympathetic branches of CN III), ptosis and ophthalmoplegia (CN III, IV, VI), proptosis (superior ophthalmic vein), and anesthesia of the forehead and upper eyelid (CN V1) 1,2 and occurs in