Clinics in diagnostic imaging (120)

Lim SA, Sitoh YY, Lim TCC, Lee JCY
Correspondence: Dr Lim Su Ann, su_ann_lim@ttsh.com.sg

ABSTRACT
Acute visual loss can be caused by retrobulbar optic neuritis, radiation optic neuropathy or ischaemic optic neuropathy. Sinusitis affecting the Onodi cell, a posterior ethmoidal air cell that has encroached on the adjacent sphenoid bone forming the optic canal, can present rarely with visual loss. We report a 60-year-old man, who developed a sudden ache on the nasal aspect of his right eye, and deterioration of the vision in his right eye. This case illustrates the typical radiological appearances of the Onodi cell on MR imaging and CT. The diagnosis of right rhinogenic optic neuritis secondary to mucocoele of the Onodi cell was confirmed at surgery. Functional endoscopic sinus surgery with decompression of the Onodi cell was performed. Physicians should be familiar with the presentation, performed. Physicians should be familiar with the presentation, diagnosis and management of this rare but important condition.

Keywords: acute visual loss, Onodi cell mucocoele, retrobulbar optic neuritis, rhinogenic optic neuritis, sphenoethmoidal sinus
Singapore Med J 2008; 49:84-7; quiz 88.