Sphenoethmoidal air cell sinusitis: A rare cause of recurrent optic neuritis

PURPOSE: To describe the clinical presentation, imaging characteristics and management of a rare case of Onodi cell sinusitis associated with optic neuropathy. OBSERVATIONS: A 46-year-old male presented to the emergency department with progressive left eye vision loss over the course of ten days. The constellation of findings from this patient's history, physical, and fundoscopic exam, as well as CT and MR imaging led to the diagnosis of Onodi air cell sinusitis complicated by optic neuropathy. The patient's symptoms resolved fully and vision returned to baseline with oral antibiotics. CONCLUSIONS AND IMPORTANCE: The sphenoethmoidal air cell, also known as the Onodi cell, is an anatomic variant of the paranasal sinuses whose spatial relationship with important neurovascular structures carries significant clinical implications when it becomes inflamed or infected. Our case of Onodi cell sinusitis complicated by optic neuropathy demonstrates how vision loss secondary to sinusitis may resolve with oral antibiotic treatment. We additionally review the relevant anatomy, clinical course and treatment of Onodi cell pathologies.