Is sphenoid sinus opacity significant in patients with optic neuritis?

Purpose Optic neuritis secondary to sinus disease is an infrequent but well -documented association. When a patient presents with signs of optic nerve dysfunction and orbital inflammation the significance of widespread sinus d isease on radiology is clear and the management is straightforward. We pres ent a group of patients with isolated optic neuritis and radiological evide nce of sphenoethmoiditis and discuss the clinical relevance of this finding . Methods We reviewed the notes of 11 patients with optic neuritis who, becau se of atypical headache, underwent neuroimaging revealing sphenoid sinus op acity. Six patients had endoscopic drainage of the sphenoid sinus; 4 were t reated medically. Results Sinus contents included fungal infection (2), mucopurulent material (5), polyps (1) and necrotic tumour (1). Narrowing of the optic canal due to chronic osteomyelitis was found in 1 patient with irreversible optic atr ophy. Visual loss was reversible in 6 patients. Pour patients had normal ra diological findings after treatment. Two patients had recurrent optic neuri tis with sphenoid sinusitis on MRI scan, resolving on treatment, during the 4 year follow-up period. Conclusions Possible mechanisms of nerve damage in this situation include d irect spread of infection, occlusive vasculitis and bony deficiency in the wall of the sinus. Patients presenting with isolated optic neuritis and aty pical headache should be scanned; an opaque sphenoid sinus in the context o f visual loss should not be dismissed as coincidental but assumed to be pat hological and the patient referred for drainage. Sphenoid sinusitis is an u ncommon but treatable cause of optic neuritis.