What is blepharospasm?
It is a repetitive and involuntary spasmodic contraction of the orbicularis muscle (the muscle around the eye), which causes abnormal positions and movements (dystonia).
Essential or primary blepharospasm is bilateral and may be accompanied by involuntary movements of the neck, face or mouth, which only disappear when the patient is asleep.
It is usually a process which advances gradually, increasing in intensity and frequency little by little. The forced closing of the eyelids may lead to visual disturbances.
What causes it?
Blepharospasm is one of the most common facial dystonias.
It can be caused by:
- A neurological functional disturbance in the central nervous system
- Side effects of certain drugs
- Lack of lubrication on the ocular surface that can cause increased eyelid activity in an attempt to evenly distribute insufficient or poor-quality lacrimal fluid
Another common disorder is hemifacial spasm, which, although not a dystonia, affects the muscles on one side of the face, causing irregular and continual involuntary movements, which can also affect the eye.
In many cases, hemifacial spasm occurs due to compression of the facial nerve by an artery or as the result of a trauma.
How can it be prevented?
Blepharospasm cannot be prevented, but it is important to detect it early. Given that, sometimes, symptoms may be confused or underestimated, it is likely that a large part of the population suffers from it without knowing.
In many cases, blepharospasm is associated with an ophthalmological problem, when, in reality, it relates to a neurological factor. In addition, if the dystonia starts in childhood, it is common for it to spread to other muscle groups. Therefore, early diagnosis and treatment of this condition is key, avoiding the complications associated with repeated abnormal postures.
- Uncontrollable blinking
- Forced closure of the eyes
- Reduced vision (in severe cases)
The treatment consists of ocular protection with sunglasses, eye drops and the application of botulinum toxin (a substance which is injected to temporarily relax the muscles and prevent them from contracting).
Although it is 90% effective, in the most severe cases, recourse to surgery called myectomy of the orbicularis muscle and the depressor muscle is required. The surgery involves the partial or complete removal of fibres from one of the muscles in the upper eyelid to prevent it from continuing to close involuntarily.
- Botulinum toxin