Determination of morphological and morphometric properties of musculus levator palpebrae superioris and evaluation in terms of clinical procedures

Levator palpebrae superioris muscle is a thin, triangular muscle specialized as a retractor of superior tarsus. In eye surgery, anatomy of it and related neighboring structures is quite important. Our research involved 100 adult orbits of 50 human cadavers of Department of Anatomy of Istanbul Faculty of Medicine. Clinical Research Ethics Committee of our Faculty approved the study (date:31.03.2021; number:155281). Morphologic and morphometric properties and relationships of levator palpebrae superioris muscle were evaluated. Morphological variations of it were discovered in 11 orbits. Length of medial and lateral edges of levator palpebrae superioris muscle, as well as width and thickness of 1/3 proksimal, 1/3 middle, and 1/3 distal parts of it were measured and statistically compared according to side and gender. Number of branches of superior branch of oculomotor nerve entering 1/3 proksimal (47), 1/3 middle (154), and 1/3 distal (37) parts of levator palpebrae superioris muscle were determined. Additionally, width and thickness of frontal nerve before it divided into its terminal branches were measured. Superior transverse ligament was found meanly 3.19+2.06mm behind levator palpebrae superioris muscle in 87 orbits and just above the muscle-levator aponeurosis junction in 13 orbits. Superior transverse ligaments were classified into four types based on their medial, middle, and lateral anteroposterior lengths. Finally, tarsus superior's medial (6.14+1.18mm), middle (7.91+1.32mm), and lateral (6.29+1.24mm) heights were measured and morphological classification of it was made according to these heights. Finally, we believe that our study will help to improve success of invasive procedures and reduce complications related with orbit.