Inferior ophthalmic vein

At a glance

English

Inferior ophthalmic vein

Latin (TA2)

Vena ophthalmica inferior

System

Vein

Region

Head

Side

Paired, left and right

About the inferior ophthalmic vein

Blood from the lower orbit is collected by the inferior ophthalmic vein. It begins in a fine venous network on the front of the orbital floor and the medial wall, and runs back through the lower orbit, lying on top of inferior rectus. It is the smaller of the two ophthalmic veins; the superior ophthalmic vein drains the upper part of the orbit and shares much of the work.

On its way it takes in veins from inferior rectus, inferior oblique and lateral rectus, from the lower conjunctiva and from the lacrimal sac, and it also receives some of the vorticose veins that leave the eyeball at its equator. These tributaries give it a territory covering the lower eye muscles and the soft tissues beneath the eye.

Towards the back of the orbit the vein splits in two. One branch passes out of the orbit by the inferior orbital fissure to end in the pterygoid venous plexus of the infratemporal fossa. The other passes back to the superior orbital fissure and drains into the cavernous sinus, either by its own opening or, more often, after uniting with the superior ophthalmic vein. The ophthalmic veins have no useful valves, so this double ending means blood can pass between the face, the deep tissues behind the jaw and the inside of the skull.

Those links are why infection of the face or orbit can reach the cavernous sinus. In orbital and periorbital cellulitis, swelling inside the orbit can press on the inferior ophthalmic vein; the rise in venous pressure adds to oedema of the lids and conjunctiva. Its connection with the pterygoid plexus also offers a path for spread of infection from dental or deep facial sources.

Course and drainage

Begins at

Begins in a fine network of veins at the front of the orbital floor and on its medial wall.

Drains into

Splits in two: one branch leaves by the inferior orbital fissure for the pterygoid plexus; the other passes back by the superior orbital fissure to the cavernous sinus, often after uniting with the superior ophthalmic vein.

Drains

Drains inferior rectus, inferior oblique and lateral rectus, the lower conjunctiva, the lacrimal sac and part of the eyeball through vorticose veins.