Prevalence of Onodi Cells in Korean Based on Computed Tomography

Abstract

Received May 29, 2015 Revised June 26, 2015 Accepted June 27, 2015 Address for correspondence Ji Sun Kim, MD, PhD Department of OtorhinolaryngologyHead and Neck Surgery, Eulji Hospital, Eulji University College of Medicine, 68 Hangeulbiseok-ro, Nowon-gu, Seoul 01830, Korea Tel +82-2-970-8276 Fax +82-2-970-8275 E-mail vicky96@eulji.ac.kr Background and ObjectivesZZThe Onodi cell is the posterior-most ethmoid air cell that lies superior to the sphenoid sinus, and has intimate relationship with the optic nerve. The aim of this study was to evaluate Onodi cell prevalence, protrusion and bony dehiscence of the optic nerve in Korean population using computed tomography (CT). Subjects and MethodZZA retrospective analysis was performed on 129 Korean patients who consecutively underwent CT between January 2014 and December 2014. The presence of Onodi cells and protrusion and bony dehiscence of the optic nerve were analyzed using 3-dimensional CT images. ResultsZZA total of 70 males and 59 females were studied. Onodi cells were present in 61 (47.3%) patients but in 88 CT slides (34.1%); this consisted of 27 Onodi cells found bilaterally (44.3%), 18 on the right side only (29.5%), and 16 on the left only (26.2%). Of the total 61 patients with Onodi cells, the optic nerve protrusion and dehiscence were present in 34.4% and 23.8% of the studied CT slides. There was no statistically significant relationship between the presence of Onodi cells and protrusion and bony dehiscence of the optic nerve. ConclusionZZIn our study, Onodi cells were found in almost half of the patients. This prevalence is higher than previously reported in the literature. In patients with Onodi cells, the optic nerve protrusion and dehiscence were present in about 1/3 and 1/5 of the total slides, respectively. Therefore, the identification of these cells is essential prior to endoscopic sinus and skull base surgery to prevent potential complications. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(12):855-8