Blepharospasm is a focal dystonia involving the eyelid closing and surrounding facial muscles, that results in increased blinking and spasms of involuntary eye closure, which can be severe enough to impair vision. The involuntary eyelid spasms can be worsened by bright lights, wind, dry eyes and with stress (e.g. such as when driving).
Most cases are “idiopathic” in that an identifiable cause is not found, and is presumed to be due to dysfunction of the circuitry deep in the brain, in an area known as the basal ganglia. This brain area is important in shaping the patterning of movement. Sometimes, this condition can be caused by medications (e.g. anti-psychotic and some anti-depressant medications, hormone replacement therapies, and benzodiazepines).
A related condition is known as Apraxia of Lid Opening (ALO), which can sometimes occur in conjunction with blepharospasm, and causes difficulty opening the eyelids, following an eye blink.
Blepharospasm can also occur together with dystonic movements of the face, jaw, tongue and swallowing muscles.
Treatment
Possible treatments include:
- Medications such as clonazepam, trihexyphenidyl, baclofen and tetrabenazine typically produce modest relief of symptoms. There are potential side effects and people need to remain on them for control of symptoms.
- Botulinum toxin injections are the first line therapy for blepharospasm. More than 95% of patients with blepharospasm report significant improvement. Side effects in 2- 5 % include dry eyes, droopy eyelids and bruising. These are temporary (last no longer than 3 months). Treatment needs to be repeated 3-4 times per year.
- Surgery (e.g. myectomy of the orbicularis oculi muscle) is reserved for medically refractory cases.
For more information see the NIH Fact Sheet on Blepharospasm.