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Levator palpebrae superioris muscle

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Last Updated: 05 September 2020

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General | Latest Info

Levator palpebrae superioris muscle

Details
ActionsElevation of upper eyelid
AntagonistPalpebral part of orbicularis oculi muscle
ArteryMuscular branches of ophthalmic artery and supraorbital artery
InsertionSuperior tarsal plate and skin of upper eyelid
NerveSuperior division of oculomotor nerve
OriginInferior surface of lesser wing of sphenoid
Identifiers
FMA49041
LatinMusculus levator palpebrae superioris
TA22052
TA98A15.2.07.020

Levator palpebrae superioris is one of the muscles of the eyelids. It arises from the inferior surface of the lower wing of the sphenoid bone. From this point, it diverges anteriorly to insert into: skin of upper eyelid superior tarsal plate fibres inserted into superior tarsal plate are largely smooth muscle and they are supplied by sympathetic division of the autonomic nervous system. Often, these muscle fibres are considered as separate from the rest and are termed superior tarsal muscle. The rest of muscle is innervate by superior division of oculomotor nerve. Levator palpebrae superioris acts to elevate and retract upper eyelid. Dysfunction of muscle results in either partial or complete ptosis with or without loss of active eyelid elevation. Potential aetiologies include: injury to sympathetic innervation arising anywhere from brain through superior cervical ganglion to muscle; it may be present with Horner's Syndrome oculomotor nerve palsy alternatively, in facial nerve palsy, action of levator palpebrae superioris may go unbalanced due to loss of function of orbicularis oculi muscle. This results in persistent eye opening.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Structure

The function of levator palpebrae superioris muscle is to raise the upper eyelid and to maintain upper eyelid position. Levator palpebrae superioris muscle origin is periosteum of lesser wing of sphenoid bone, superior to optic foramen. Muscle travels anteriorly along superior aspect of orbit superior to superior rectus muscle. Supraorbital artery and frontal and lacrimal nerves are superior to levator muscle in orbit. Distally muscle widens and becomes tendon sheath know as levator aponeurosis in the region of Whitnall's ligament, which is a transverse suspensory ligament. Whitnall's ligament appears to be part of the pulley system allowing horizontal levator muscle to become more vertical levator aponeurosis. Whitnall's ligament also forms part of the complex Koornneef orbital septae, which provide support to globe and orbital components and also serve as an accessory locomotor system. Levator aponeurosis has lateral and medial wings attaching to respective canthal tendons. Lateral horn is more robust than the medial horn. Levator aponeurosis has multiple insertions: anteriorly into upper eyelid skin, inferiorly on anterior surface of upper tarsal plate, and with indirect extensions to superior conjunctival fornix. Posterior to levator aponeurosis is superior tarsal muscle, which is smooth muscle that also attaches to superior tarsal plate. Levator palpebrae superioris is not smooth muscle but skeletal muscle.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Clinical significance

Damage to this muscle or its innervation can cause ptosis, which is drooping of the eyelid. Lesions in CN III can cause ptosis, because without stimulation from oculomotor nerve, Levator palpebrae cannot oppose the force of gravity, and eyelid droops. Ptosis can also result from damage to adjoining superior tarsal muscle or its sympathetic innervation. Such damage to sympathetic supply occurs in Horner's syndrome and presents as partial ptosis. It is important to distinguish between these two very different causes of ptosis. This can usually be done clinically without issue, as each type of ptosis is accompanied by other distinct clinical findings. Ptosis seen in paralysis of Levator palpebrae superioris is usually more pronounced than that seen due to paralysis of superior tarsal muscle.


Muscles of Eye Movement

Levator palpebrae superioris has strong associations with superior rectus muscle, superior tarsal muscle, and orbicularis oculi. The superior branch of the Oculomotor nerve dually innervates superior rectus muscle and levator palpebrae superioris muscles, allowing synchronous elevation of the upper eyelid during upward gaze. The location of superior tarsal muscle is posterior to levator aponeurosis extending from the inferior aspect of levator palpebrae superioris to the superior aspect of tarsal plate. It is sympathetically innervate and assists with eyelid retraction. Levator palpebrae superioris is major antagonistic muscle of orbicularis oculi, whose primary function is eyelid closure.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Relations

Key facts about the levator palpebrae superioris muscle

OriginLesser wing of sphenoid bone
InsertionSuperior tarsal plate, skin of upper eyelid
ActionElevates superior eyelid
InnervationOculomotor nerve (CN III)
Blood supplyOphthalmic artery, supraorbital artery

Levator palpebrae superioris lies superior to the superior rectus muscle, which separates it from the eyeball. Both muscles are enclose by connective tissue sheaths which are fuse along their related surfaces. Sheaths are separate only in their anterior parts at level in which tendons of these muscles are separate. The interval between them is filled by a thick connective tissue plate onto which superior conjunctival fornix attaches. In addition, Levator palpebrae superioris is attached to check the ligament of the superior rectus. All of these connections contribute to coordinate simultaneous contraction of these two muscles. As Levator palpebrae superioris fans out as wide aponeurosis, lateral fibers pass between orbital and palpebral parts of lacrimal gland to attach to orbital tubercle. Medial fibers run adjacent over reflected tendon of superior oblique muscle.


Levator palpebrae superioris muscle

Levator palpebrae superioris the only muscle involved in raising the superior eyelid. A small portion of this muscle contains a collection of smooth muscle fibres - know as superior tarsal muscle. In contrast to LPS, superior tarsal muscle is innervate by sympathetic nervous system. Attachments: Originates from the lower wing of sphenoid bone, immediately above the optic foramen. It attach to the superior tarsal plate of the upper eyelid. Actions: elevate upper eyelid. Innervation: levator palpebrae superioris is innervate by oculomotor nerve. Superior tarsal muscle is innervate by sympathetic nervous system.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Function

Lps has reciprocal innervation with main structure responsible for eyelid closure, OO muscle. Just prior to blink, LPS is inhibited and OO motoneurons generate short, high - frequency discharge bursts resulting in OO contraction. At the end of blink, OO activity ceases and the eye opens with the return of LPS activation to its tonic baseline. Blinks may be spontaneous, reflexive, or voluntary, with different portions of OO contracting for different types of blinks. The pretarsal portion of OO is responsible for involuntary blinks, and the preseptal portion, for voluntary blinks and intentional eyelid closure. Spontaneous blinks are highly dependent on dopaminergic neurotransmission. Premotor, or supranuclear, control of eyelid function and mechanisms of LPS disinhibition are not entirely understood, but the cerebral cortex, basal ganglia, and superior colliculus are thought to play a role. Functional imaging studies suggest that medial frontal lobes, including supplemental motor area, are involved in control of blinking. The role of basal ganglia in eyelid control, while not as extensively studied as their role in eye movements, has been studied in normal and dopamine - deficient animal models. This control is mediated primarily through nigro - collicular connections, as summarized in Table 1. Substantia nigra pars reticulata has an inhibitory effect on SC via - aminobutyric acid. Experimental biochemical manipulation of SC confirms its role in inhibition of blink reflex. Enhancement of SC inhibition with GABA agonist results in decreased blink rate and increased reflex blink excitability. It is also known that dopamine depletion similarly decreases the blink rate. Even in the absence of EOA, abnormal eyelid and blink function are evident in Parkinsons disease and fit the model well, with decreased spontaneous blink rates and increased blink reflex excitability with prolonged voluntary blinks due to delayed return of LPS to baseline tonic activity. In contrast, decreasing SC inhibition with GABA antagonist increases blink rate and decreases blink reflex excitability. This demonstrated role of dopaminergic transmission and role of basal ganglia in eyelid function may also be involved in genesis of EOA in movement disorders. The primary structure responsible for eyelid elevation is the LPS muscle. Sympathetically innervated Mullers muscle contributes to a very small degree. Lps is innervate by superior division of oculomotor nerve, with motoneurons originating from both LPS muscles in single midline central caudal subnucleus of the oculomotor nucleus in midbrain. Tonic activation of LPS muscles in awake state maintains eye opening at all times other than when inhibition of LPS occurs to permit eye closure. The premotor source of this tonic activation is not know, but may be located in the periacqueductal gray supraoculomotor area in midbrain just dorsal to oculomotor nucleus.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Lesson Summary

Levator palpebrae superioris is muscle located in the upper eyelid that allows you to keep your eyes open. This muscle is comprised of both skeletal and smooth muscle. Skeletal muscles are muscles that are usually attached to bones and are under voluntary control. Smooth muscles are found in various organs and blood vessels throughout the body and are under involuntary control. Levator palpebrae superioris muscle that works to raise and retract upper eyelids. Since this muscle is comprise of both skeletal and smooth muscle fibers, person can both voluntarily and involuntarily raise and retract their upper eyelids. This muscle is able to move upper eyelids because it is inserted into the skin of upper eyelids, as well as into the superior tarsal plate of upper eyelids. Medical Disclaimer: information on this site is for your information only and is not a substitute for professional medical advice.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Introduction

Fatty deposition in levator aponeurosis / levator palpebrae superioris muscle is cause of aponeurotic blepharoptosis. Fatty degeneration predominantly occurs in LPS muscles but occasionally extends to levator aponeurosis. An increase in fatty deposition in levator aponeurosis / LPS muscle causes weakness of tractional force to upper eyelid. Previous studies show that fatty deposit in aponeurosis / LPS muscle is more prevalent in East Asians than in Caucasians, suggesting that fatty degeneration has greater impact on clinical aspects of aponeurotic blepharoptosis in East Asian patients. As far as we can determine, however, influence of fatty degeneration on surgical outcomes of transcutaneous aponeurotic repair has not been explored in this population. Levator aponeurosis is composed of anterior and posterior layers. The anterior layer of levator aponeurosis is thick, robust fibrous tissue that reflects superiorly few millimetres above the tarsal plate and continues to the orbital septum. The posterior layer, composed of thinner fibrous tissue, attaches to the tarsal plate and extends to subcutaneous tissue. The distal end of ALLA, called the white line, is easily identifiable after incision of the orbital septum, and is often used as a reference point to determine the amount of advancement of levator aponeurosis during blepharoptosis surgery. We, therefore, choose to use the white line to estimate the degree of fatty degeneration in levator aponeurosis / LPS muscle. We evaluate vertical distance from distal end of ALLA to distal point of fatty deposit, indicating area without fatty deposit, during transcutaneous aponeurotic repair and then analyse the relation between that length and surgical outcomes.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Surgical technique

We have recently described transconjunctival levator aponeurosis repair without resection of Mullers muscle. This technique, which is present here, enables advancement of levator aponeurosis, similar to transcutaneous approach, but without the need for exposure through skin incision. It is based on advancing levator aponeurosis, while temporally detaching Mullers muscle from its insertion site, and is effective in correcting cases of aponeurotic ptosis with good or excellent levator muscle function. It maintains normal anatomical contour of the upper eyelid, preserves its function, and allows for quick recovery. By avoiding skin incision, there is no external scarring and operating time is shorten. This technique may therefore be preferred by many patients who are reluctant to undergo ptosis surgery because of possible external scar. It should also be adopted by surgeons who prefer levator aponeurosis advancement rather than transconjunctival resection of Mullers muscle for ptosis repair. This review discusses advantages and drawbacks of this technique, criteria for patient selection, description of surgical procedure, and possible complications. Selection of patients who may benefit from this surgical technique is an essential step in successful post - operative outcome. Suitable candidates are those patients with aponeurotic ptosis with good or excellent LPS muscle function, no excessive upper eyelid laxity, fine superior palpebral crease, and who are reluctant to have skin incision. Patients with significant degree of Dermatochalasis of eyelid are less suitable for this surgical method. Other factors such as Brow ptosis or forehead laxity should also be taken into consideration. Patients should be advised of the possibility of postoperative worsening of Dermatochalasis and upper eyelid laxity as result of Brow descent, which is frequently seen after correction of ptosis. Ptosis surgery could be combined with browpexy or forehead lift,. However, not in patients in whom precise size or shape of double eyelid is expected and in those who have thick eyelids that require reduction. Outline of transconjunctival levator surgery is present The Operation is usually performed under local anesthesia. Local anesthetic solution is injected with 30 gauge needle in the subcutis of the eyelid, which is then evert with traction sutures, and under conjunctiva. Dissection is carried out with a microdissection needle or pair of sharp - point monopolar forceps powered by Ellman Surgitron radio - frequency generator or by a high - frequency electrosurgical unit. Conjunctiva is incised 1 mm above the upper border of the tarsal plate. Mullers muscle is cut from the tarsus, leaving 1 / 3 of the lateral part intact. Very thin glossy fascia lies between Mullers muscle and levator aponeurosis. Aponeurosis is dissected from the frontal aspect of tarsus up to level of 2 - 3 mm below the superior border of tarsus and then incised horizontally and dissected laterally in front of preserved part of Mullers muscle.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Blood Supply and Lymphatics

The internal carotid provides most of Levator palpebrae superioris blood supply via branches of the ophthalmic artery. Four arterial systems direct blood to Levator palpebrae muscle: lacrimal, supratrochlear, and supraorbital arteries and muscular branches of ophthalmic artery. These branches eventually connect to a superior peripheral arcade, providing blood supply to the superior aspect of the upper eyelid. The superior peripheral arcade connects medially and laterally with the superior marginal arcade, which provides blood supply to the margin of the upper eyelid. These two arcades form vast anastomosis with blood from branches of internal and external carotids. Internal carotid supplies the majority of blood to superior peripheral arcade via branches previously state. The external carotid provides additional blood to superior peripheral arcade medially via angular artery and laterally via superficial temporal artery. This complex anastomosis maintains rich blood supply to lateral palpebrae superioris. In terms of venous drainage, muscles of orbit drain via superior and inferior ophthalmic veins. Superior ophthalmic vein will eventually drain into the cavernous sinus, and inferior ophthalmic vein will drain into the pterygoid venous plexus. In regards to lymphatic drainage, it was previously thought that medial upper eyelid drain medially along angular artery and lateral upper eyelid lymph drain laterally to preauricular and parotid nodes. There is a recent change regarding eyelid lymphatics drainage based on lymphoscintigraphy in human subjects. Upper eyelid lymphatics, which would include Levator palpebrae superioris muscles, are believed to entirely drain laterally to preauricular / parotid lymph nodes, and then to deep cervical lymph nodes. From here, lymph drainage follows conventional drainage patterns.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Nerves

Cranial nerve III includes four of six extraocular muscles of the eye as well as levator palpebrae superioris muscle of the eyelid and, via projections to ciliary ganglion, small intraocular muscles that control constriction of pupil and shape of lens. Unlike the other two oculomotor nervesthe abducens nerve, which innervates lateral rectus muscle, and trochlear nerve, which innervates superior oblique musclethe, oculomotor nerve has more than one functional component. It contains GSE component for innervation of extraocular and levator palpebrae superioris muscles and GVE parasympathetic component for innervation of ganglion that in turn innervates intraocular muscles. Oculomotor nerve fibers traverse tegmentum and exit the brain in interpeduncular fossa medial to crus cerebri and then pass rostrally to orbit with other oculomotor nerves. The Gse component of cranial nerve III arises from motor neurons in oculomotor nucleus proper, which lie in the dorsomedial part of the rostral half of the midbrain tegmentum. This component includes four muscles that insert on globe of the eye: inferior oblique muscle, which extort, elevates, and abducts the eye; medial rectus muscle, which adducts the eye; inferior rectus muscle, which depress, extorts, and adducts the eye; and superior rectus muscle, which elevate, intorts, and adducts the eye. The Oculomotor nuclear complex comprises several nuclei in addition to the GSE main nucleus, including the EdingerWestphal nucleus and several accessory oculomotor nucleithe nucleus of Darkschewitsch, interstitial nucleus of Cajal, and nuclei of posterior commissure. These accessory nuclei receive inputs from a variety of visual - and vestibular - related sources and contribute to vertical and smooth - pursuit movements of eyes direct by GSE component. Edingerwestphal nucleus and more rostral anterior median nucleus contain preganglionic parasympathetic neurons that project via oculomotor nerve to ipsilateral ciliary ganglion, which lie deep to posterior boundary of the eye. Postganglionic parasympathetic fibers from ciliary ganglion supply ciliary muscle, which affects the shape of lens for focusing on near objects, and sphincter pupillae muscle. Consensual pupillary light reflex of evoking bilateral constriction of pupils when light is shin in one eye depends on the pathway from retina to olivary pretectal nucleus, which in turn projects bilaterally via posterior commissure to anterior median and EdingerWestphal parasympathetic nuclei. In this context, it should be noted that dilation of pupil is accomplished by action of sympathetic innervation that arises from preganglionic neurons in intermediolateral column of spinal cord and affects dilator pupillae muscle fibers via postganglionic neurons of superior cervical ganglion. Damage to the ventral region of midbrain may result in a syndrome called superior alternating hemiplegia, which is motor impairment on the contralateral side of the body combined with lateral and downward deviation of the eye on the ipsilateral side due to lower motor neuron lesion of oculomotor nerve.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Sources

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

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