The anatomical and morphological variations of levator palpebrae superioris muscle and its clinical relevance

Abstract

Abstract The muscle that primarly retracts the upper eyelid is called the levator palpebrae superioris muscle. For eyelid surgery, a thorough understanding of its anatomical and morphological variations as well as the variations of surrounding tissues is necessary. This study conducted on 100 adult orbits in Department of Anatomy, Istanbul University, used an exploratory, descriptive research design. Ethics committee approval was obtained from the Istanbul Medical Faculty Clinical Research Ethics Committee (date:31.03.2021; number:155281). The anatomical and morphological variations of levator palpebrae superioris muscle and its relationship with the superior ophthalmic vein were evaluated. Variations of levator palpebrae superioris muscle were discovered in 11 of 100 orbits. Single (9%), double (1%) and triple (1%) accessory muscle slips were observed. The variations associated with the superior ophthalmic vein were 5%. The origin of accessory muscle slips showed variation as the accessory muscle slips originated either from the proximal or distal half of levator palpebrae superioris muscle. Also the insertions of accessory muscle slips were variable, as they inserted to levator aponeurosis, trochlea, lacrimal gland, lateral orbital wall or the fascia of superior ophthalmic vein. Consequently, levator palpebrae superioris muscle variations are essential for the superior ophthalmic vein as they can directly compress it. Ophthalmologists in particular, practitioners, should be aware of the anatomical and morphological variations of the levator palpebrae superioris muscle.