Superior ophthalmic vein

The superior ophthalmic vein is a prominent vein of the orbit that is seen on CT and may be enlarged or tortuous in various disease entities.

Gross anatomy

The vein forms at the confluence of several veins within the superior orbit above the medial palpebral ligament: the angular, supratrochlear and supraorbital veins. It courses medially towards the trochlea between the optic nerve and ophthalmic artery (inferior) and the superior rectus muscle (superior). As it curves laterally in the posterior orbit, it exits the fibromuscular cone to leave the orbit via the superior orbital fissure between the frontal nerve and trochlear nerve. It drains directly into the cavernous sinus.

The vein drains parts of the orbit such as the globe, extra-ocular muscles and the lacrimal gland.

The mean diameter of the vein is 2 mm and normal sizes range from 1 to 2.9 mm ². A threshold value of 2.5 mm has also been proposed ³.

Related pathology

Enlarged or tortuous superior ophthalmic veins may be seen in:

• carotid-cavernous fistula
• ophthalmic vein varix
• raised intracranial pressure
• Graves disease
• orbital pseudotumour

Reversible bilateral enlargement of the superior ophthalmic veins is often seen in intubated patients ³. The superior ophthalmic veins may be hyperdense on CT due to thrombosis, including in cases of orbital cellulitis.