Levator Palpebrae Superioris: An Anatomical Update

Abstract

The levator palpebrae superioris (LPS) muscle is the main retractor of the upper eyelid, responsible for elevating the upper eyelid and maintaining it in an open position. Sound knowledge of its anatomy and adjacent structures is essential for eyelid surgery. Work from researchers and anatomists over the years continue to enrich our understanding in the anatomy of the LPS. In this review, we present an update on the anatomy of the LPS and its surgical implications. Important adnexa such as Whitnall's ligament, intermuscular-transverse ligament and Müller's muscle are also covered.

Blepharoptosis following ocular surgery

“…Most hypotheses focus on damage to the levator complex. Anatomically, the LPS originates from the lesser wing of the sphenoid bone superolateral to the optic foramen and fans out as it travels anteriorly along the superior orbital wall and above the superior rectus muscle, reaching its maximum diameter of 18 mm at the musculotendinous transition to the levator aponeurosis [2]. The levator aponeurosis descends from Whitnall's ligament and splits into an anterior and posterior lamella.…”

“…Müller's muscle arises from the undersurface of the LPS and inserts into the superior tarsus and is innervated by the sympathetic nervous system [4]. The medial horn of the levator aponeurosis is thought be thinner and structurally weaker than the lateral horn [2]. Ptosis can be caused by injury to any of these structures, their insertions, or the innervation to the eyelid retractors.…”

“…Ptosis following ocular surgery can be treated with high rates of success [2,5,7,[41][42][43][44][45]. These treatments restore or recreate the structure-function relationships within the upper eyelid using multiple surgical approaches (Fig.…”

“…It has been postulated that a tight eyelid speculum reduces blood flow to the LPS, horizontally stretches the eyelid, and that contraction of the orbicularis against the rigid speculum causes levator dehiscence. It is also thought that sustained compressive forces from the speculum can cause crush injury to the delicate upper eyelid musculature and myoneural or myovascular connections, ultimately leading to muscle injury and subsequent ptosis [2,[17][18][19].…”

Advanced Single-Stage Eyelid Reconstruction

“…4 Whitnall's ligament redirects the levator from a horizontal to vertical orientation in the upper eyelid. 4 Whitnall's ligament redirects the levator from a horizontal to vertical orientation in the upper eyelid.…”