Common tendinous ring

Eyemuscles

Common tendinous ring (Latin: Anulus tendineus communis), also known as the annular tendon or Zinn’s ring, is a anatomical structure of the orbit that serves as the origin for the four rectus muscles of the eye. These muscles include the superior, inferior, medial, and lateral rectus muscles, which are crucial for controlling the movements of the eye.

Structure[edit | edit source]

The common tendinous ring is located at the apex of the orbit, surrounding the optic canal and part of the superior orbital fissure. It is a tendinous ring from which the four rectus muscles of the eye originate. The ring is divided into two parts: a larger part, which gives rise to the superior, inferior, and medial rectus muscles, and a smaller part, for the origin of the lateral rectus muscle. The optic nerve and ophthalmic artery pass through the center of the ring, entering the orbit from the cranial cavity.

Function[edit | edit source]

The primary function of the common tendinous ring is to serve as an anchoring point for the rectus muscles of the eye. These muscles play a critical role in the movement and stabilization of the eye, allowing for precise control of gaze direction. The arrangement of the muscles around the ring facilitates a wide range of eye movements, including elevation, depression, adduction, and abduction.

Clinical Significance[edit | edit source]

Abnormalities or injuries to the common tendinous ring can lead to strabismus, a condition characterized by misalignment of the eyes. This can result from trauma, inflammatory conditions, or congenital defects affecting the tendinous ring or the originating muscles. Surgical interventions involving the eye muscles, such as those for correcting strabismus, require careful consideration of the common tendinous ring's anatomy to avoid damaging the optic nerve or affecting the blood supply to the eye.