Anatomical Variations of the Optic Nerve in the Sphenoid Sinus: Do Ethnic Variations Matter?

Sonika Kanotra; Seerat Bashir; Preeti Sharma; Shweta Purbi; Misba Manzoor; Kshitij Gupta

doi:10.1007/s12070-023-03798-y

Anatomical Variations of the Optic Nerve in the Sphenoid Sinus: Do Ethnic Variations Matter?

Indian J Otolaryngol Head Neck Surg. 2023 Sep;75(3):1943-1949. doi: 10.1007/s12070-023-03798-y. Epub 2023 Apr 20.

Authors

Sonika Kanotra¹, Seerat Bashir¹, Preeti Sharma¹, Shweta Purbi¹, Misba Manzoor², Kshitij Gupta³

Affiliations

¹ Department of E.N.T., Head and Neck Surgery, Govt. Medical College and S.M.G.S. Hospital, Jammu, India.
² Department of Radio-Diagnosis, Govt. Medical College, Jammu, India.
³ ASCOMS, Jammu, India.

PMID: 37636678
PMCID: PMC10447864 (available on 2024-09-01)
DOI: 10.1007/s12070-023-03798-y

Abstract

There are several variations in the anatomical relations of the optic nerve with the sphenoid sinus. Proper understanding of these variations is clinically important to minimize injuries associated with surgical procedures that involve the sphenoid sinus. CT scans of paranasal sinuses obtained prior to any endoscopic surgery in the sphenoid sinus area is useful for designing operative strategies. Ethnic variations in sinonasal anatomy have been documented. The objective was to study the pattern of relationship between optic nerve and the sphenoid sinus using computerized tomographic imaging in a north Indian population, to compare our findings with previous studies in different ethnic groups and find out if ethnic variations in such a relationship matter. A prospective study was conducted on 300 patients who underwent computed tomography of the paranasal sinuses from Sept 2020 to June 2021. Relationship of optic nerves to the sphenoid sinuses was categorized according to DeLano classification. Pneumatization of the anterior clinoid process and bony dehiscence of optic nerve was also observed. Type 1 position of optic nerve was seen in 69.3%, Type 2 in 20.9%, Type 3 in 3% and Type 4 in 6.8% of sinuses. The pneumatization of anterior clinoid process (ACP) was observed in 10.5% and the bony dehiscence of optic nerve was noted in 6.5% sinuses. Bony dehiscence of optic canal had associated ACP pneumatization in 64.1% sinuses.The variability of the relation of optic nerve to the sphenoid sinus even in the persons of same ethnicity precludes a definite role of ethnicity in these variations. Other factors possibly contributing to such a relationship have been discussed.

Keywords: Anterior clinoid process; CT scan; Ethnic variations; Optic nerve; Sphenoid sinus.

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