Acquired ptosis: Classification and evaluation

Abstract

A detailed description of the anatomy of the eyelid and levator complex may be found elsewhere in this text. Knowledge of this anatomy is paramount for appropriate surgical reconstruction of ptotic eyelids. Early authors described in great detail the relationship of the levator palpebrae superioris muscle with its insertion into the tarsus, orbicularis muscle, and skin [1–4]. Recent investigators have improved our understanding of the relationship of the levator aponeurosis with the tarsal plate and anterior skin structures [5, 6]. The origin of the levator muscle is at the apex of the orbit, just above the annulus of Zinn. The length of the levator is approximately 60, 40 mm of which is muscular and the distal 15–20 mm of which is fi brous aponeurosis. The superior transverse ligament, also known as Whitnall's ligament, is a condensation of the anterior sheath of the levator muscle.