Levator palpebrae superioris muscle in human fetuses: Anatomical findings and their clinical relevance

Abstract

Accessory medial muscular bellies of the levator palpebrae superioris muscle and broad lateral insertion of its aponeurosis into tissue near the lacrimal gland have been reported as rare variations in adults. The anatomy of this muscle was studied in orbits of ten human fetuses between the 5th and 10th months of gestation. In each of the dissected orbits, the levator palpebrae superioris muscle had a broad lateral insertion into the capsule of the lacrimal gland or the periorbita, in this period of development. In addition, medial accessory muscles of the levator or singular muscle fibers within fibrous bands that inserted near the trochlear region and the medial portion of the upper eyelid were present in 70% of the fetuses, either unilaterally or bilaterally. These findings demonstrate new unreported aspects of levator palpebrae superioris development and morphology. Our findings suggest that an initial broad anterior primary anlage of the muscle is followed by secondary atrophy of lesser used marginal portions of this muscle, which are replaced by delicate connective tissue. These findings might force new considerations about diagnostic and therapeutic approaches to congenital mobility disorders of the levator palpebrae superioris muscle, such as blepharoptosis or eyelid retraction. The clinical relevance of our results are discussed along with a review of the embryogenesis of extraocular muscles and soft tissue of the orbit.

Extraocular eye muscles in human fetuses with craniofacial malformations: Anatomical findings and clinical relevance

“…A dissected collection of nine normal human fetuses (6th to 10th months after gestation) with normal, intact orbital features served as a comparative group. The special anatomy of this group was reported earlier (Plock et al, 2005). All fetuses belonged to the collection of fetuses at the Institute of Anatomy and Cell Biology, University of Wuerzburg.…”

“…Radiological documents about these anomalies are rare (Ingham et al, 1986;Munoz, 1996;Chan and Demer, 1999). We recently demonstrated new anatomical findings of the levator palpebrae superioris muscle in human fetuses (Plock et al, 2005). Anomalies of the extraocular muscles in patients with craniofacial malformations, like Crouzon, Apert, Pfeiffer, or Goldenhar-Gorlin syndromes, are only rarely reported and contain small numbers of patients for each malformation syndrome (Weinstock and Hardesty, 1965;Aleksic et al, 1976;Cuttone et al, 1979;Diamond et al, 1980;Nelson et al, 1981;Mansour et al, 1985;Carruthers, 1988;Pollard, 1988;Fries and Katowitz, 1990;Greenberg and Pollard, 1998;Coats and Ou, 2001).…”

A Study on Variations of Levator Palpebrae Superioris Muscle with Its Embryological Basis and Clinical Significance

“…Amonoo-Kuofi and Darwish (1998) reported bilateral accessory LPS muscle between superior oblique and LPS that ran from the lessser wing of the sphenoid to the skin of the upper lid, but these muscle were not bipartite (9) . Fetal LPS exhibit a broad aponeurotic insertion on the upper lid and the connective tissue of the lacrimal gland, often with medial and lateral accessory muscular slips or fibrous bands arising from LPS (Plock et al 2005) (10) . Changes during embryogenesis upto 24 months postnatally may result in LPS undergoing adaptation (11) .…”

“…Complete absence of the Levator palpebrae superioris muscle. (2,3) . Accessory levator muscle slips may be associated with congenital eyelid retraction or blepharoptosis (4) .…”

Bilateral lateral bipartite levator palpebrae superioris muscles

“…Amonoo-Kuofi and Darwish (1998) reported bilateral accessory LPS muscles between superior oblique and LPS that ran from the lesser wing of the sphenoid to the skin of the upper lid, but these muscles were not bipartite. Fetal LPS exhibit a broad aponeurotic insertion on the upper lid and the connective tissue of the lacrimal gland, often with medial and lateral accessory muscular slips or fibrous bands arising from LPS (Plock et al, 2005). Changes during embryogenesis up to 24 months postnatally may result in LPS undergoing adaptations (Sevel, 1988).…”