Sinusitis, A Rare Cause of Optic Neuritis Following an Endoscopic Endonasal Approach

Introduction: The endoscopic endonasal approach (EEA) is a common minimally invasive technique to treat conditions of the skull base, sellar region, orbit, and sinuses. Sinusitis is as uncommon complication of EEA, with an occurrence of 1-2%. The optic nerve courses from the posterior globe, through the orbit, and the optic canal, which is adjacent to the sphenoid sinus. Optic neuritis, which presents as eye pain, photophobia, and visual loss, is a rare complication of sphenoid sinusitis. Optic neuritis can occur secondary to demyelination, ischemia, infiltration, compression, and trauma, while only rarely reported to occur secondary to direct spread of local infection. Here we report the first case of optic neuritis secondary to sinusitis after an endoscopic endonasal approach for optic nerve decompression. Case Report: The patient presented after two years of left sided visual loss. An MRI demonstrated a homogenously enhancing lesion of the left optic nerve sheath extending to the clinoid process, consistent with an optic nerve sheath meningioma. EEA was performed for optic nerve and left orbital apex bony decompression in preparation for stereotactic radiosurgery. The surgery was uneventful and the periorbita and nerve sheath were left intact. On post-operative day eight the patient was seen for routine follow-up in otolaryngology clinic and reported having improvement of their vision and normal nasal endoscopy. Fractionated radiation therapy (50.4Gy/28fx) was subsequently performed. Four months after surgery the patient developed left eye pain, facial pain, headache, and worsening left sided visual decline. Mucoid discharge was noted on repeat nasal endoscopy concerning for underlying infection. Cultures taken demonstrated methicillin resistant staphylococcus aureus. The purulent nasal discharge worsened, and endoscopic debridement was performed. The patient was treated with a course of Augmentin, Prednisone and Budesonide irrigations with improvement in their facial pain and visual changes. At most recent follow-up the patient had no recurrence of their symptoms. Conclusion: To our knowledge we are the first to report optic neuritis occurring secondary to sinusitis after an endoscopic endonasal approach for optic nerve decompression. Successful treatment can be achieved with a combination of debridement, antibiotics, and steroids. Publication History Article published online: 27 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany