Abstract

A 69-year-old woman presented 2 days after painless visual loss of her left eye, which developed over 45 min. She was otherwise systemically well. Twelve weeks prior, she had left-sided frontotemporal headache which lasted for 8 weeks. Examination showed left visual acuity to perception of hand movement only and a relative afferent pupillary defect; her fundi looked normal. The rest of neurological examination was normal including temporal arteries. Her past medical history was noncontributory. Her erythrocyte sedimentation rate was 74 at the time of visual loss, which spontaneously improved to 45–55 mm/h on repeated testing over 3 months. CT brain and orbits showed opacity of the left sphenoid sinus and cavernous sinuses. MRI orbits showed inflammatory changes at the left orbital apex. She underwent functional endoscopic sinus surgery and sphenoidectomy with thorough clearance of the sphenoid sinus. Histology confirmed a fungal ball from within the sinus. The diagnosis was a noninvasive fungal sinusitis. Our patient's inflammatory markers normalised after treatment but her vision never recovered. We hypothesise that her vision loss was due to infarction of her optic nerve secondary to local inflammation from fungal sinusitis. We highlight fungal sinusitis as a rare cause of optic neuropathy.