Editor,—We describe a 68 year old man who suffered from progressive visual loss in his left eye to no light perception within 10 days and subtle involvement of ipsilateral cranial nerves V(1) and VI. Both computed tomography (CT) and magnetic resonance imaging (MRI) showed a left optic canal lesion with expansion to the superior lateral (anterior clinoid) and inferior walls of the optic canal. Left supraorbital craniotomy was performed by a neurosurgeon. A mucocoele containing turbid fluid in the left strut with compression to the optic nerve was found during the operation. After removal of the lesion, the patient’s best corrective visual acuity was improved to hand movements.

Though visual loss related to mucocoeles of the paranasal sinuses is not rare the frontal, ethmoid, and sphenoid sinuses are most often implicated. Only rarely has a pneumatised anterior clinoid been reported as a primary location for a mucocoele associated with visual loss.1 2 We report a case of anterior clinoid mucocoele producing optic neuropathy and other subtle cranial neuropathies. We emphasise the relation of the optic strut to the optic canal and the superior orbital fissure in producing a symptom complex distinct from optic neuritis and orbital apex syndrome.