Progressive Blindness Caused by an Unusual Sphenoid Sinus Dehiscence

Abstract

Figure. CT demonstrates afocal inflammatory process in theposterior sphenoid sinus on the left, with developmental dehiscence of the lateral wallof the optic nerve canal (arrow) allowing the inflammatory process to extendinto theoptic canal and apexof theorbit (A). Contrast-enhanced axialMRI reveals enhancement of theinflammatory process extendingfrom theposterior sphenoid sinusinto theorbital apexand around the optic nerve (arrow). Inflammation of the medial rectus muscle and periorbital area isalso noted(B). Coronal MR images at thelevel of theorbital apex(arrow) (e) and at thelevel of theproximal optic nerve (arrow) (D) reveal marked inflammatory enhancement in theoptic sheath of theoptic nerve.