Dorsal view of the sellar region. The MOCR and middle clinoid are distinct anatomical structures with different surgical implications. The MOCR is located at the most lateral margin of the tuberculum sellae and lies between optic nerve and supraclinoidal ICA. The middle clinoid is located in the parasellar region between the paraclinoidal and cavernous ICA, and may form an osseous ring by joining the anterior clinoid process. This should always be considered before attempting surgical removal of the middle clinoid to increase access to the parasellar region. (Image courtesy of JC Fernandez-Miranda)