Marcus Gunn jaw-winking ptosis is a congenital disorder associated with synkinetic movements of the upper eyelid involuntarily contracting while the jaw is chewing.
Marcus Gunn jaw-winking ptosis or jaw wink ptosis is a type of condition when the upper eyelid droops over the eye and is associated with synkinetic movements of the upper eyelid moving while the jaw is chewing. Synkinesis is a neurological symptom in which a voluntary muscle movement causes a simultaneous involuntary contraction of other muscles. In jaw wink ptosis, muscle movement while chewing causes involuntary movement of the eye muscle.
Marcus Gunn jaw-winking ptosis is a congenital disorder (present at birth). It is usually seen only on one side but rarely seen on both. The condition affects men and women equally.
What causes jaw wink ptosis?
There are several theories concerning why jaw wink ptosis occurs, but the most preferred theory, which is believed by most, is that it’s a result of abnormal nerve innervation (nerve supply) between the motor branches of two nerves. One is the facial nerve, called the trigeminal nerve, that controls the muscles of chewing (mastication) and the other is the superior branch of the oculomotor nerve that controls the muscle of the eye (levator palpebrae superioris).
Since Marcus Gunn jaw-winking ptosis is a congenital disorder, it is rarely acquired later in life. However, it may develop after eye surgery, syphilis, trauma and pontine tumors (brain tumors). In cases of acquired jaw wink ptosis, spontaneous remission may occur, whereas the congenital form continues to persist without any improvement.
What are the signs and symptoms of jaw wink ptosis?
Typically, the condition is first observed by the mother while breastfeeding or bottle-feeding her baby, which is often seen as an elevation of the affected eyelid when the child feeds.
The characteristics signs of jaw wink ptosis include:
- Blepharoptosis: (when the upper eyelid droops over the eye), usually on one side and rarely on both.
- Upper eyelid movement: seen on the following,
- Mouth opening
- Movement of the jaw toward the opposite side
- Chewing
- Sucking
- Protrusion of the jaw
- Clenching jaw/teeth
- Swallowing
Furthermore, other signs and symptoms of jaw wink ptosis can include:
- Ocular (eye):
- Strabismus (squint or crossed eye) may be seen in 50 to 60 percent of cases
- Anisometropia (when the eyes have varying refractive power)
- Amblyopia (lazy eye)
- Systemic:
- Cleft lip/Cleft palate
- CHARGE syndrome (coloboma, heart defects, choanal atresia, growth retardation, genital and ear abnormalities)
- Renal calculi (kidney stones)
How is jaw wink ptosis diagnosed?
A doctor can make a clinical diagnosis of the condition based on the mother’s history and by observing the signs and symptoms.
Additionally, other diagnostic tests may be performed, such as:
- Measuring the extent of jaw wink ptosis: the amount of jaw-winking is measured with a millimeter ruler and categorized into
- Mild < 2 mm
- Moderate 2 to 5 mm
- Severe ≥ 6 mm
- Testing for abnormal oculocardiac (eye-heart) reflex: this reflex may be associated with the condition and doctors test it by performing an electrocardiogram (EKG or ECG) prior to surgery.
How is jaw wink ptosis managed?
Though spontaneous remission of acquired jaw wink ptosis is possible, the congenital form continues to persist without any improvement. Hence, it requires treatment options, such as:
- Conservative treatment: If amblyopia (vision loss in one eye) is present, doctors may treat it aggressively with occlusion therapy and/or correction of anisometropia (unequal refractive power in both eyes) before any ptosis surgery. Doctors would advise regular follow-up.
- Surgery: There are several surgical procedures to correct jaw wink ptosis, such as removal of part of the levator muscle of the eye without extensive dissection and damage to eye/eyelid structures, sling procedures, etc. The surgeon would recommend an appropriate technique based on the extent of the jaw wink ptosis.
Complications of surgery
Prognosis is usually good in the majority of cases. However, complications can occur even two to four weeks after surgery, and may result in the following:
- Undercorrection or overcorrection
- Lagophthalmos (incomplete or defective closure of the eyelids)
- Suture granuloma (non-cancerous, inflammatory mass at the site of sutures/stitches)
- Sling slippage in sling procedures
- Asymmetric eyelid crease causing cosmetic concerns
- Inflammation and infection
- Amblyopia (lazy eye) can occur in 30 to 60 percent of cases; however, with observation and treatment, it can be treated successfully.