Anomalous Bilateral DeLano Type III Trans-Sphenoidal Optic Nerve Course in an Iraqi Patient

Abstract

Anomalous trans-sphenoidal course of the optic nerve represents a rare anatomical variant with important clinical implications. Because the optic nerve may bulge into or traverse the sphenoid sinus in the setting of extensive sphenoid sinus pneumatization, such unrecognized anomalies increase the risk of optic nerve or visual pathway injuries during endoscopic or surgical procedures. Early recognition on preoperative imaging is therefore crucial. We are presenting a case study of an eighteen-year-old Iraqi male who underwent a paranasal computed tomography at Baghdad Medical City; clinical history and presenting complaint were unavailable. Imaging demonstrated marked sino-nasal asymmetry with a severe left-sided nasal septum deviation, a larger right inferior turbinate, mild left Schneiderian membrane thickening, an asymmetric multi-septate sphenoid sinus with a left lateral recess, bilateral anterior clinoid process pneumatization, and small right Onodi cells. Most notably, both optic nerves followed an anomalous DeLano type III trans-sphenoidal course, which is an uncommon but clinically significant sino-nasal anatomic variant. Careful preoperative assessment of sphenoid sinus pneumatization, septation, and optic-nerve relationships is essential to prevent iatrogenic optic-nerve injury and to guide endoscopic sinus and skull-base procedures, including functional endoscopic sinus surgery (FESS). Radiology reports should explicitly document these variants, and significant findings should prompt multidisciplinary discussion.