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Superior Ophthalmic Vein at Computed Tomography

The superior ophthalmic vein is the main intraorbital vein and is connected by abundant collaterals, directly or indirectly, with all other intraorbital veins. It is always filled at orbital phlebography in normal cases, provided an adequate phlebographic technique is used (BRISMAR 1974) and is also usually demonstrable following selective injection into the maxillary artery. Occasionally the superior ophthalmic vein is filled following selective injection into the internal carotid artery; the diagnostic implications of such a finding have been the subject of recent reports by HACKER & PORRERO (1969) and TORNOW & PISCOL (1971). The superior ophthalmic vein is formed behind the pulley of the superior oblique muscle by the union of tributaries from the supraorbital and angular veins. Initially it courses posteriorly but soon turns laterally to enter the muscular cone, crossing under the superior rectus muscle (anterior segment). It appears again on the lateral side of this muscle and then runs postero-medially following the lateral border of the superior rectus muscle (middle segment). The vein then descends to leave the orbit through the superior orbital fissure (posterior segment) and empties into the cavernous sinus.