Ophthalmic artery

Ophthalmic artery is a branch of the internal carotid artery, arising as the first branch distal to the cavernous sinus. Ophthalmic artery, via its branches, supplies all the structures in the orbit as well as some structures in the nose, face and meninges.

Course:

The ophthalmic artery emerges from the internal carotid artery, as soon as the latter emerges from the cavernous sinus. This point of origin lies medial to the anterior clinoid process.

The artery then runs anteriorly and enters the orbit through the optic canal with the optic nerve. It then runs forward and crosses the optic nerve to reach the medial wall of the orbit. Here it gives off numerous branches.

Branches of ophthalmic artery:

Central retinal artery:

Also known as the “central artery of the retina”, it is a small branch that pierces the meningeal sheaths of the optic nerve to gain access to the nerve. It then runs in the substance of the optic nerve and enters the eyeball at the center of the optic disk.

At this point, the central retinal artery divides into branches that are end arteries. These end arteries supply the inner retinal layers.

Lacrimal artery:

It is one of the largest branches of the ophthalmic artery, and arises just as the latter enters the orbit. It runs along the superior edge of the lateral rectus muscle and supplies the lacrimal gland, eyelids and conjunctiva.

Muscular branches:

These are numerous small branches that arise in two groups; superior muscular branches and inferior muscular branches. They supply the extraocular muscles.

Ciliary arteries:

These are numerous small branches and can be divided into two groups; posterior ciliary arteries and anterior ciliary arteries.

  • Posterior ciliary arteries:
    These are 1 – 5 small branches that subsequently branch into long and short posterior ciliary arteries. These branches perforate the sclera in the vicinity of the optic nerve and macula to supply the posterior uveal tract.
  • Anterior ciliary arteries:
    These are derived from the muscular branches of the ophthalmic artery. They enter the eyeball near the corneoscleral junction.

Supraorbital artery:

It passes anteriorly along the medial border of the superior rectus muscle and then through the supraorbital foramen to supply the muscles and skin of forehead.

Ethmoidal arteries:

There are two ethmoidal arteries; anterior ethmoidal artery and posterior ethmoidal artery. Both enter the nose.

Supratrochlear artery:

Also known as the frontal artery, it is one of the terminal branches of the ophthalmic artery, arising at the point where the latter travels posterior to the trochlea.

The supratrochlear orbit leaves the orbit by piercing the orbital septum at the medial angle. It travels alongside the supratrochlear nerve and ascends to the forehead. Here it supplies the skin, muscles and pericranium.

The supratrochlear artery of one side anastomoses with the supraorbital artery of the other side.