Optic foramen location on computed tomography

Abstract

Background: This study aimed to identify the location of the optic foramen in relation to the anterior sphenoid sinus wall, which is essential information for surgeons in planning and performing endoscopic transnasal surgery.

Methods: Computed tomography scans of 200 orbits from 100 adult patients with no abnormalities were examined. The results included the location of the optic foramen in relation to the anterior sphenoid sinus wall and the distance between them, as well as the distance from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence in the posterior sphenoid sinus.

Results: The optic foramen was anterior to the anterior sphenoid sinus wall in 48.5% of orbits, and posterior in the remaining 51.5%. The mean distance from the optic foramen to the anterior sphenoid sinus wall was 3.82 ± 1.25 mm. The mean distances from the optic foramen and the anterior sphenoid sinus wall to the carotid prominence were 7.67 ± 1.73 and 7.95 ± 2.53 mm, respectively.

Conclusion: The optic foramen was anterior to the anterior wall of the sphenoid sinus in approximately half of the orbits examined in this study, and posterior in the remaining half. The mean distance from the optic foramen to the anterior sphenoid sinus wall of the sphenoid sinus was 3.82 ± 1.25 mm.

Keywords: Optic nerve; Orbit; Sphenoid sinus; Tomography.

Fig. 1.

Symmetrical configuration of the optic foramina (anterior–anterior). The left and right optic foramina (solid white arrows) are anterior to the anterior sphenoid sinus walls (black filled arrows).

Fig. 2.

Symmetrical configuration of the optic foramina (posterior–posterior). The left and right optic foramina (solid white arrows) are posterior to the anterior sphenoid sinus walls (black filled arrows).

Fig. 3.

Asymmetrical configuration of the optic foramina (posterior–anterior). The right optic foramen is anterior to the anterior sphenoid sinus wall, while the left optic foramen is posterior to the anterior sphenoid sinus wall. The optic foramina are marked with solid-white arrows. The anterior sphenoid sinus walls are marked with blackfilled arrows.

Fig. 4.

Relationship of the anterior sphenoid sinus wall to the carotid prominence. The anterior sphenoid sinus wall is marked with blackfilled arrows. The carotid prominence is marked with solid-white arrows.