Background: Sphenoid sinus mucoceles are rare. In many cases they are asymptomatic until they become advanced. Due to their proximity to several important neurovascular structures, sphenoid sinus mucoceles can lead to an array of compressive and inflammatory neuro-opthalmologic complications. They have also been described as mimicking pituitary tumors; as such a patient with complications of sphenoid sinuses can present to the primary care doctor, the endocrinologist, the neurologist or the ophthalmologist. Of the numerous clinical manifestations, visual loss is of the most concern as this may be irreversible.
Case Report: A middle aged woman in whom an imaging of the head revealed an incidental sphenoid mucocele presented several months after the initial imaging, with acute and worsening bilateral loss of vision. She had no endocrine abnormalities. She was immediately admitted, treated promptly with antibiotics and steroids, and underwent endoscopic surgery with marsupialization of the sphenoid sinus. Despite a successful and uneventful surgical course, she did not completely recover her vision. Several months after the surgery, her vision still remains impaired.
Conclusions: In a patient presenting with loss of vision, the suspicion of a sphenoid sinus mucocele must be entertained in the differential diagnosis. When the diagnosis of a sphenoid sinus is confirmed, it is imperative that prompt surgical treatment is undertaken as permanent blindness could result from delay in management. Pre-operative visual acuity is the sole determinant of the extent of recovery of vision. If time is wasted before surgical decompression, patients may lose their vision irreversibly.

Keywords: Sphenoid Sinus, pyomucocele, Blindness, pyomucocele