Marcus Gunn Jaw Wink

Marcus Gunn Jaw Wink Ptosis is an example of a congenital abnormal innervation connecting two groups of normally unrelated muscles. While this type of ptosis does not usually improve with time, children learn how to minimize its appearance. The condition is thought to result from a misdirection of the fifth cranial nerve fibers into a branch of the third cranial nerve that supplies the levator muscle.

Overview Features

Marcus Gunn Jaw Wink Ptosis is rare and is characterized by poor levator function. It is an example of synkinesis and causes the eyelid to open/wink (increase in the palpebral fissure) with movements of the jaw. Usually, this jaw movement causes a brief and synchronous raising of the eyelids. Children with significant ptosis may need to adapt their movements to accommodate this condition. They may 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 lids.

Causes

While the cause of congenital ptosis is 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 may also have amblyopia (“lazy eye”), strabismus (eyes that are not perfectly aligned or straight), refractive errors, astigmatism, or blurred vision. Drooping of the eyelid could lead to an undesired facial appearance.

Evaluation of the Patient

At Idaho Eyelid and Facial Plastic Surgery, we perform a complete ophthalmic exam with particular attention to visual acuity. Some observations worth considering:

• In a series of congenital ptosis cases, the incidence of amblyopia was measured to be 20%, of which 3% was attributable to droopy eyelids.
• Previously, chin elevation posturing was considered a sign of fusion and indicated a low risk for amblyopia; however, it has recently been shown that chin elevation does not rule out the presence of significant amblyopia.
• In a series of 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.
• Given that the superior rectus is often involved in this condition, full extraocular motion needs to be carefully evaluated.

Concurrent Anatomic Abnormalitites

Marcus Gunn concurrent abnormalities may include any of the following:

• Strabismua – crossed eyed or misaligned eyes (50-60% of cases)
• Superior rectus palsy – poor movement or weakness in the muscle that elevates the eye
• Double elevator palsy – poor movement or weakness in the levator palpebrae superioris and the superior rectus muscle
• Anisometropia – different refractive power between the eyes
• Amblyopia, or lazy eye – coinciding along with ptosis associated with Marcus Gunn

Marcus Gunn Jaw-winking Ptosis

In 1883, Marcus Gunn discovered an unusual type of congenital ptosis with a rare associated movement of the affected lid. The levator muscle has cranial nerves supplying it. Marcus Gunn Jaw Wink Ptosis is thought to be a congenital misdirection of the fifth cranial nerve fibers into a branch of the third cranial nerve. Ptosis severity is classified in a matrix, or a 3 x 3 grid evaluating 9 combinations of ptosis (mild, moderate, severe) in jaw-winking (mild, moderate, severe). Different positions of the matrix correspond to several ways to correct the defect.

Treatments

Congenital ptosis is most often treated by ophthalmic plastic and reconstructive surgeons who specialize in diseases and conditions affecting the eyelids, lacrimal (tear) system, the orbit (bone cavity around the eye), and adjacent facial structures. At Idaho Eyelid and Facial Plastic Surgery, we can help you determine the best path forward.

Congenital ptosis is treated surgically, with the specific operation based on the severity of the ptosis and the strength of the levator muscle. The surgical procedure is evaluated in conjunction with levator function along with the severity of ptosis. Function is typically categorized as poor (less than 4 mm), fair (5 to 7 mm), and good (more than 8 mm). In cases of severe ptosis with less than 2 mm of levator function, suspension of the lid to the frontalis muscle is the procedure of choice.

If the visual axes are not obscured by the ptotic lid, it is best to defer treatment until the child is ages 3 or 4. 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). When the ptosis interferes with vision, surgery is performed at an earlier age to allow for proper visual development.