Marcus Gunn Syndrome, also known as Marcus Gunn Jaw-Winking Syndrome or Jaw-Winking Phenomenon, is a rare congenital condition that affects the muscles controlling eye and jaw movements. It is typically present at birth and is characterized by an abnormal response of the eyelid when the jaw moves.
The main feature of Marcus Gunn Syndrome is an involuntary eyelid movement known as jaw-winking. This means that when the affected individual opens their mouth or chews, their eyelid on the same side may raise or wink. The degree of eyelid movement can vary from mild to pronounced.
Although the exact cause of Marcus Gunn Syndrome is not fully understood, it is believed to result from a developmental abnormality in the nerves that control the muscles involved in eye and jaw movements.
Most cases of Marcus Gunn Syndrome do not require treatment. However, in severe cases where the jaw-winking significantly affects vision or causes social discomfort, surgical intervention may be considered. The goal of surgery is to correct the abnormal muscle connections and improve the coordination between eye and jaw movements.
It is important for individuals with Marcus Gunn Syndrome to have regular eye examinations to monitor their vision and ensure any necessary interventions are provided.