The parasellar region from the transcranial approach. The interclinoidal ligament is medial to the oculomotor nerve and forms the medial margin of the oculomotor triangle. The anterior and posterior petroclinoidal ligaments, which form the lateral and posterior margins of the oculomotor triangle, have been transected to expose the horizontal segment of the cavernous ICA. The cranial nerves III, IV, V1, and VI (not shown here) continue anteriorly into the superior orbital fissure. (Image courtesy of JC Fernandez-Miranda)