Acute Compressive Optic Neuropathy Secondary to an Onodi Cell Mucocele: A Case Report

Abstract

Aims: To report a rare case of compressive optic neuropathy secondary to an Onodi cell mucocele and to emphasise the importance of early recognition of rhinogenic causes of acute vision loss. Case Presentation: A 51-year-old woman with aspirin-exacerbated respiratory disease and previous endonasal surgery for recurrent nasal polyposis presented with acute, rapidly progressive unilateral visual loss. Examination showed counting-fingers vision that deteriorated to light perception, a relative afferent pupillary defect, painful eye movements, and a normal optic fundus. Magnetic resonance imaging demonstrated a posterior ethmoid/Onodi cell mucocele compressing the intracanalicular optic nerve without optic nerve enhancement. Intravenous corticosteroids and ceftriaxone were administered while transfer for definitive surgery was arranged. Endoscopic posterior ethmoidectomy, sphenoidotomy, and decompression were performed 5 days after presentation. No visual improvement was observed during the one-year follow-up. Discussion: Onodi cell mucoceles are uncommon but vision-threatening lesions because of the close anatomical relationship between the posterior ethmoid sinus and the optic nerve. Published outcomes are heterogeneous: severe preoperative visual impairment is associated with poorer recovery in observational series, whereas the effect of the interval to decompression is less consistent. Adjunctive corticosteroid and antibiotic therapy has not been established as a substitute for surgical relief of compression. Conclusion: Acute unilateral optic neuropathy with a normal fundus should prompt urgent neuroimaging and consideration of sinonasal disease, particularly in patients with chronic rhinosinusitis, nasal polyposis, or previous sinus surgery. Expedited multidisciplinary assessment and surgical decompression are warranted when optic nerve compression is identified, although profound initial visual loss may limit recovery.