Endonasal Endoscopic Anatomy of Optic Nerve and Opthalmic Artery in Optic Canal and Orbital Apex

Introduction: Different pathologies such as tumors, traumas, vascular and inflammatory processes can affect the optic nerve, resulting in visual deficit. Optic nerve decompression is performed as a standart treatment method for many of these pathologies. The Aim of the study is to define the relationship of optic nerve and opthalmic artery in optic canal and orbital apex.

Materials and Methods: In this study the optic nerve decompression via transsphenoidal andoscopic approach was perfomed to 10 head cadavers. After removal of the inferior and medial walls of the optic canal, the longitudinal length measurements of the decompression performed to the medial and inferior optic canal were made. The relationship between the origin of the opthalmic artery and the internal carotid artery, the relationship between the optic nerve and the ophthalmic artery and the course of the ophthalmic artery in orbital apex were evaluated. The diameter measurements of the ophthalmic artery were done.

Results: The longitudinal length measurement of the decompression made to the medial and inferior optic canal which is the decomression amount of the optic canal was measured between a minimum of 6 mm and a maximum of 8 mm (a mean of 6.6 ± 0.69 mm) on the right side and between a minimum of 5 mm and a maximum of 10 mm (a mean of 7 ± 1.33 mm) on the left side. Ophthalmic artery diameters were measured between a minimum of 1 mm and a maximum of 1.2 mm (a mean of 1.03 ± 0.06 mm) on the right side and between a minimum of 1 mm and a maximum of 1.5 mm (a mean of 1.14 ± 0.2 mm) on the left side. The opthalmic artery was observed to be located superomedial to the ICA in 6 and superolateral in 4 of the cadavers on the right side. On the left side the opthalmic artery was observed to be located superior to the ICA in 1, superomedial to the ICA in 6 and superolateral to the ICA in 3 of the cadavers.

The origin of the opthalmic artery was observed to be located inferior to the optic nerve in 5 of the cadavers, inferolateral to the optic nerve in 2, inferomedial to the optic nerve in 3 on the right side. The origin of the opthalmic artery was observed to be located inferior to the optic nerve in 5 of the cadavers, inferolateral to the optic nerve in 1, inferomedial to the optic nerve in 4 on the left side.

Conclusion: Endoscopic optic nerve decompression has many advantages and currently one of the standart treatment methods for various pathologies. To be on the safe side, it is extremely important to know the anatomy of this region and reliable landmarks may provide orientation to the endoscopic anatomy, prevent serious complications and therefore determine the safe surgery limits.

 

MissingLinkText

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
07 February 2025