Lateral rectus muscle

Last revised by Craig Hacking on 27 Dec 2021

The lateral rectus muscle is one of the six extraocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI).

Lateral rectus, along with the other rectus muscles, arises from the annulus of Zinn, the common tendinous ring at the apex of the orbit that surrounds the optic canal 1.

Lateral rectus runs anteriorly on the lateral surface of the eye and inserts into the lateral surface of the sclera just posterior to the junction of cornea and sclera 2.

Branches of the ophthalmic artery, itself a branch of the internal carotid artery.

Lateral rectus is unique among the extraocular muscles in being supplied by the abducens nerve.

The action of the lateral rectus is to abduct the eye (see figure 1) 1. Unlike most of the other extraocular muscles, it has no significant contribution to movement in the other ocular axes.

Rectus comes from the Latin rectos, meaning straight 1.

  • oculomotor nerve palsy
    • as the lateral rectus and superior oblique muscles are the only extraocular muscles not supplied by the oculomotor nerve, the unopposed force generated by these muscles results in depression and abduction of the affected eye
  • abducens nerve palsy
    • as the lateral rectus is the primary ocular abductor, abducens nerve palsy results in adduction of the affected eye, due to unopposed effect primarily of the medial rectus muscle
    • because of its long subarachnoid course and location in the Dorello canal, abducens nerve palsy can be an early sign of increased intracranial pressure

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