Sphenoid sinus mucocele with unilateral blindness.

Mucoceles of the sphenoid sinus are rare and may frequently remain undiagnosed until symptoms due to compression of surrounding structures set in. In such cases, the optic nerve, because of its close proximity to the sphenoid sinus, is at risk, and pressure exerted by the mucocele may result in visual impairment. A case of a sphenoid sinus mucocele with sudden-onset unilateral blindness as the only presenting symptom has been described. Early diagnosis and prompt surgical intervention enabled the vision to be restored completely.