Onodi sinusitis presenting with orbital apex syndrome.

This article reports the unusual presentation of a patient with an intraconal abscess secondary to sinusitis in an onodi cell in a healthy 63 year old Chinese female. She presented with limited extraocular movements, decreased corneal sensation, rapid drop in visual acuity and signs of optic neuropathy, in the absence of any inflammatory signs in the right eye. MRI scans showed a well-encapsulated mass in the posterior two thirds of the orbit, with the presence of an onodi cell on the right side. She underwent an extended lateral orbitotomy, which revealed frank pus that was positive for Staphylococcus aureus. She was treated with intravenous antibiotics with complete resolution of her presenting signs.