Eyelid Support

    The complexity of eyelid anatomy reflects the competing functional demands of providing support for the lid margins while allowing mobility of the lids. Primary eyelid support is provided through the bony attachment of the canthi with a secondary level of support from the orbicularis muscle and its fascial attachments.

    The medial canthus is medial to the globe with a rigid fixation to the orbital wall. By contrast, the lateral commissure overlies the lateral part of the globe and is mobile, having up to 6 mm of vertical movement and 2 mm of lateral movement.6 These anatomical landmarks are determined by the medial and lateral palpebral ligaments, which provide the ligamentous support for the tarsal plates. The palpebral ligaments are commonly referred to as the medial and lateral canthal tendons on account of the pretarsal orbicularis fibers that contribute to their superficial surfaces. In addition, the orbicularis muscle and more particularly the fascia on its deep surface forms a continuous fibrous network of support through the orbicularis attachment to the tarsal plates and canthal tendons, and to the lateral orbital rim via the firm fibrous attachment provided by the orbicularis retaining ligament and the lateral orbital thickening.