Anatomical Structures Adjacent to the Ciliary Ganglion
The ciliary ganglion is located between the optic nerve medially and the lateral rectus muscle laterally, positioned near the orbital apex in the posterior orbit. 1, 2
Primary Adjacent Structures
The ciliary ganglion occupies a specific anatomical position with consistent neighboring structures:
- Optic nerve (medial): The ganglion sits at a mean distance of 1.47-2.9 mm lateral to the optic nerve 1, 2
- Lateral rectus muscle (lateral): Located at a mean distance of 2.88-10.4 mm medial to the lateral rectus muscle 1, 2
- Orbital apex (posterior): Positioned in the posterior orbit, approximately 16-17 mm anterior to the common tendinous ring, typically at 50-75% of the distance between the posterior globe and the orbital apex 2, 3
Additional Surrounding Structures
The ganglion exists within a complex neurovascular environment:
- Ophthalmic artery: The ganglion lies in proximity to this vessel within the orbital apex region 4
- Abducens nerve (CN VI): Located near the ganglion in the orbital apex 4
- Inferior branch of oculomotor nerve (CN III): The motor (parasympathetic) root typically originates from the nerve to the inferior oblique muscle, which courses near the ganglion 4, 3
Clinical Relevance
Understanding these anatomical relationships is critical for surgical planning:
- Lateral orbital approaches carry the highest risk of ciliary ganglion injury, potentially resulting in mydriatic or tonic pupils 1, 2
- Orbital fracture repairs and procedures involving the lateral rectus muscle require awareness of the ganglion's position to avoid inadvertent damage 1, 2
- The ganglion's location in loose areolar tissue between the optic nerve and lateral rectus makes it vulnerable during dissection 1