Selective alteration of palpebral fissure form by lateral canthopexy

Abstract

A method is described for altering the shape and position of the palpebral fissure at the lateral canthus. Three steps are essential to alter shape and position. They are (1) identification of a lateral canthal soft-tissue mass consisting of periosteum, lateral canthal ligament, and orbicularis muscle, (2) extensive subperiosteal soft-tissue mobilization of the lateral canthal soft-tissue mass (LCSTM) from a point just superior to the zygomaticofrontal suture and inferiorly along the infraorbital rim to a point corresponding with a vertical line drawn from the pupil downward, and (3) cutting of all soft tissue, including orbicularis muscle from dermis to bone and from bone to conjunctiva, from the lateral canthal soft-tissue mass medially to a point equal to a vertical line drawn from the pupil downward. After tension-free shifting laterally and superiorly has been accomplished, the lateral canthal soft-tissue mass is fixed into bone with minimal overcorrection. If there is still soft-tissue skin resistance, then overcorrection is desirable. The most difficult judgments in the procedure are the amount of superior and lateral tension to be placed on the palpebral fissure. As an aid in these judgments, the lateral-most extent of the palpebral fissure should be approximately 3 mm above the medial canthus horizontally and 3 to 4 mm medial to the medial-most portion of the lateral orbital rim. If overcorrection occurs, it can be released relatively simply.