The sphenoid sinus, out of the facial sinuses, is certainly the most neglected as far as diagnosis is concerned. The surgical approach requires a detailed anatomical knowledge, considering the serious complications resulting from injuries of vital structures adjacent to this region. AIM: The objective of our research is to evaluate the anatomic relationship of the optic nerve with the sphenoid sinus making use of the computed tomography. STUDY DESIGN: Serie report. MATERIAL AND METHOD: The authors present a retrospective analysis of 203 computed tomographies of facial sinus belonging to individuals of both sexes aged 14 and over. The examinations were evaluated observing the course of the optic nerve, obtained through the degree of its projection on the wall of the sphenoid sinus. The method used was the modified classification of Delano, evaluating the absence of bone reduction (dehiscence) of the optic nerve in the sphenoid sinus. We analysed the degree of pneumatization of the sphenoid sinus, using Hammer's classification adapted by Guerrero, apart from the pneumatization of the anterior clinoidal process and pterigoid and the presence of the Onodi cell. RESULTS: Most of the patients (78.96%) presented their optic nerve with a Type 1 course. Type 2 was observed in 16.83% of the patients, Type 3 in 3.47% and Type 4 in 0.74%. The presence of dehiscence of the optic nerve in the wall of the sphenoid sinus was evidenced in 21.29% of the cases. Related to pneumatization, we noticed that the pre-selar type was observed in 6.44%, the post-selar type appeared in 39.11%, the selar type appeared in 54.45%, and the apneumatized type was not observed in any of the cases. The pneumatization of the anterior clinoidal process was verified in 10.64% of the cases, while the pterigoid process was apparent in 21.29% of the cases. The Onodi cell (sphenoetmoidal) was found in 7.92% of the cases. CONCLUSION: The presence of dehiscence of the optic nerve is related with the degree of pneumatization of the anterior clinoid and the pterigoid processes, the presence of the Onodi cell (sphenoetmoidal) and Course Types 2, 3 and 4 considered the relationship between the optic nerve and the sphenoid sinus.
optic nerve; sphenoidal sinus; computed tomography
