Ptosis Jaw-Wink

Marcus Gunn Jaw wink ptosis is an example of synkinesis (an abnormal innervation connecting two groups of normally UNRELATED muscles)

Marcus Gunn Jaw-wink ptosis does not generally improve with time, but children do tend to learn how to minimize {the} appearance

The phenomena is thought to be due to a congenital misdirection of {the} fifth cranial nerve fibers into a branch of {the} third cranial nerve that supplies levator muscle.

Overview
Features

  • Marcus Gunn Jaw wink ptosis is an example of synkinesis (an abnormal innervation connecting two groups of normally UNRELATED muscles)poor levator function
    • This causes {the} eyelid to open (increase in {the} palbebral fissure) with movements of {the} mouth

 

  • higher position of {the} ptotic eyelid on downgaze.
  • Children with significant ptosis might need to tilt their head back into a chin-up position, lift their eyelid with a finger, or raise their eyebrows in an effort to see from under their drooping eyelid(s).
  • Marcus Gunn Jaw-wink ptosis does not generally improve with time, but children do tend to learn how to minimize {the} appearance
Marcus Gunn Jaw wink ptosis is an example of synkinesis (an abnormal innervation connecting two groups of normally UNRELATED muscles) This causes the eyelid to open (increase in the palbebral fissure) with movements of the mouth

Causes

  • While {the} cause of Congenital ptosis is often unclear, {the} most common reason is improper development of {the} levator muscle. The levator muscle is {the} major muscle responsible for elevating {the} upper eyelid.
  • Children with Congenital ptosis might also have amblyopia ("lazy eye"), strabismus (eyes that are not well aligned or straight), refractive errors, astigmatism, or blurred vision. In addition, drooping of {the} eyelid might result in an undesired facial appearance.

Evaluation of {the} Patient

  • complete ophthalmic exam with particular attention to visual acuity.
    • In a series of Congenital ptosis cases incidence of amblyopia was measured to be 20% of which 3% was attributable to droopy eyelid.
    • In {the} past, {the} chin elevation posturing was considered a sign of fusion and, thus, indicating a low risk for amblyopia.
    • However, it has recently been shown that {the} chin elevation does not rule out {the} presence of significant amblyopia.
  • thorough motility examination is essential
    • in a series of a 113 patients, 31% were found to have strabismus and of these, 3% of {the} cases were believed to be caused by ptosis that disrupted binocular fusion.
    • because {the} superior rectus is often involved, full extraocular motion needs to be carefully evaluated.

Concurrent Anatomic Abnormalitites

  • Blepharophimosis might require medial canthal tendon plication5
  • Physiologic defects such as jaw-winking ptosis might require transection of {the} levator muscle as well as frontalis suspension.
  • Because of {the} levator aponeurosis resection, children needs to be performed under general anesthesia, a formula is used to determine {the} amount of levator aponeurosis resection.

Marcus-Gunn Jaw-winking Ptosis

  • In 1883 Marcus Gunn reported an unusual type of congenital ptosis with with a peculiar associated movement of {the} affected lid." Previous authors have reported Marcus-Gunn phenomena to occur in 2 to 13% of patients with "Congenital ptosis .
  • The phenomena is thought to be due to a Congenital lmisdirection of {the} fifth cranial nerve fibers into a branch of {the} third cranial nerve that supplies levator muscle.
  • Patients are classified according to {the} degree of two parameters:A 3 x 3 matrix is constructed which gives 9 combinations of ptosis (mild, moderate, severe), in jaw-winking (mild, moderate, severe). Different positions of {the} matrix correspond to one of several operations which are abdicated for {the} correction of this defect.
  • Beard reported 76% of his patients with Marcus-Gunn syndrome had an associated weakness of {the} superior rectus.
  • Incidence of amblyopia in patients with Marcus-Gunn jaw-winking ptosis is reported to be approximately 35%.
  • In a study in 1984 of 64 patients with jaw- winking ptosis, 60% were found to have amblyopia, 60% were found to have strabismus and 25% were found to have anisometropia. Twenty-five percent were found to have a double elevator palsy.
  • It has been proposed that {the} Marcus-Gunn phenomena is secondary to supranuclear etiology. The prevalence of double elevator palsy in this study tends to support {the} theory of a supranuclear lesion. In this study of 1984, of 71 patients followed for approximately 5 years, they were unable to document any objective improvement in any of their patients1 However, they felt that adults were able to control their lid position in excursion of masquerading their jaw-winking phenomena

Treatments

  • In general, if {the} visual axes are not obscured by {the} ptotic lid, it is best to defer treatment until {the} child is age 3 or 4.
  • The surgical procedure is determined by {the} amount of levator function present and {the} severity of ptosis. Function is typically categorized as poor (less than 4 mm), fear (5 to 7 mm) and good (more than 8 mm). In cases of severe ptosis in less than 2 mm of levator function, suspension of {the} lid to frontalis muscle is {the} procedure of choice.Congenital Ptosis is treated surgically, with {the} specific operation based on {the} severity of {the} ptosis and {the} strength of {the} levator muscle.
    • Conjunctival-muellers resection
    • Levator resection
    • Frontalis sling
      • Silicone
      • Fascia (autogenous or donor)
      • Supramid
  • If {the} ptosis is not severe, surgery is generally performed when {the} child is between 3 and 5 years of age ({the} "pre-school" years).
  • However, when {the} ptosis interferes with {the} child's vision, surgery is performed at an earlier age to allow proper visual development.
  • Congenital ptosis is most often treated by ophthalmic plastic and reconstructive surgeons who specialize in disease and conditions affecting {the} eyelids, lacrimal (tear) system, {the} orbit (bone cavity around {the} eye), and adjacent facial structures.

 

 

Procedures
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