The inferior rectus muscle is located within the orbit (eye socket). It is one of six muscles that control the movements of the eye. The inferior rectus muscle moves the eyeball downward. It also moves the eye inward towards the nose and rotates the top of the eye away from the nose.
Motor functions of the muscle are supplied by the oculomotor nerve. Illness or trauma affecting this nerve impacts the movement of the inferior rectus muscle. Oculomotor nerve palsy results from damage to the oculomotor nerve, which controls the inferior rectus and other muscles that move the eye. As a result, the afflicted individual will not be able to move his or her eye normally. This condition is also known as oculomotor neuropathy.
Typically, the eye is displaced downward due to nerve issues with the inferior rectus muscle. This condition can have several different causes, including diabetes, heart disease, and atherosclerosis. Surgery can raise the eyelid and focus the eye forward, but that is the extent of improvement that can be expected.