Zinn's Ligament

ZINN'S LIGAMENT, LIGAMENT, zonula Zinni, s. ciliaris (syn. lig. suspensorium lentis), is formed by fibers stretched between the ciliary body and the lens. The delicate homogeneous fibers of Z. l. begin on the inner surface of the ciliary body and end partly on the anterior, partly on the posterior surface of the lens, while a small portion of them attaches to the equator of the lens itself. The fibers of the first group (anterior) lie in the depressions between the ciliary processes. The fibers of the second group (posterior) approach the tops of the ciliary processes. The space enclosed between the fibers of Z. l. and the equator of the lens, in a meridional section, has a triangular shape and is called canalis Petiti. Through the slit-like openings between individual fibers of Z. l., this space connects with the posterior chamber of the eye. These fibers hold the lens in a certain position. Relaxation or disruption of Z. l. leads to the downward displacement of the lens. Through the fibers of Z. l., the ciliary body also influences the shape of the lens. In the state of rest of accommodation, the anterior fibers of Z. l. pull the anterior surface of the lens toward the periphery and backward, resulting in the flattening of its anterior pole. During tension of accommodation, Z. l. relaxes following the contraction of the muscle, and the lens takes on a more convex shape. Z. l. is of ectodermal origin.