Introduction
There is a rare congenital condition known as Marcus Gunn jaw-winking syndrome in which the upper eyelid moves along with the jaw movement. As a result of abnormal neural connections between muscles controlling jaw movement and those controlling eyelids, it typically appears in infancy.
Causes
An abnormal connection exists between the trigeminal nerve, which controls jaw movement, and the oculomotor nerve, which controls eyelid movements. It is usually congenital, meaning that it occurs at birth, and is not caused by external factors or trauma. It occurs during fetal development. There is no known cause for this nerve misconnection.
Symptoms
Marcus Gunn phenomenon is characterized by the involuntary movement of the upper eyelid in response to jaw movements. Common symptoms include:
-
A jaw-winker's eyelid moves upward when the jaw opens, such as when chewing, sucking, or even talking.
-
The affected eyelid may droop when the jaw is not moving, a condition called unilateral ptosis.
-
In some cases, jaw-winking is barely noticeable, but in others, it can be quite noticeable. The severity of jaw-winking varies from mild to severe.
-
Individuals who do not align their eyes properly may also suffer from strabismus (eye misalignment).
Diagnosis
Clinical evaluation is typically used to diagnose Marcus Gunn phenomenon:
-
When opening the mouth or chewing, a healthcare provider will observe the characteristic jaw-winking movement of the eyelid.
-
Doctors may perform eyelid movement tests in order to determine whether the eyelids move independently or if there is a misalignment of the eyes (strabismus).
-
While imaging studies such as MRI are not typically required for diagnosis, they may be conducted in some cases to exclude other causes of abnormal eye or jaw movements.
Treatment
There are a number of treatment options available for Marcus Gunn phenomenon, depending on the severity of the condition and whether or not it causes functional or cosmetic issues.
-
If the jaw-winking is not highly noticeable or does not interfere with vision, no treatment should be necessary. Regular monitoring is often recommended for mild cases.
-
In severe cases, surgery may be required to correct the ptosis or reduce the jaw-winking movement. The goal of surgery is generally to improve the appearance of the eyelid and reduce functional impairments such as vision obstructions.
-
A drooping eyelid may be corrected with ptosis surgery to improve vision and appearance.
-
In some cases, surgery may be performed to weaken the nerves controlling the jaw and eyelids.
-
To align the eyes properly, vision therapy or additional eye surgeries may be necessary if strabismus is present.
Prevention
Since Marcus Gunn phenomenon occurs during fetal development, there are no known methods to prevent it. However, early diagnosis and treatment can help address symptoms and improve outcomes.
Conclusion
An abnormal eyelid movement in response to jaw motion is the hallmark of Marcus Gunn phenomenon, a rare congenital condition. Early diagnosis and surgical treatment can improve appearance and function if it interferes with vision or causes cosmetic concerns. It does not typically cause serious medical issues, but may require treatment if it interferes with vision or causes cosmetic concerns.
