What is blepharospasm?
Blepharospasm describes an involuntary closure of both eyes. This can present as rapid frequency blinking, forced eyelid closure, or an inability to initiate eyelid opening (apraxia of eyelid opening). Often, blepharospasm can be a combination of these different manifestations of the condition. In addition, blepharospasm can involve other parts of the face and neck in 30% of patients. This can give the appearance of lip and mouth movements, or tongue and jaw spasm. Occasionally, the muscles of the larynx (voice-box) can also become affected, producing a hoarse or whispering voice.
Blepharospasm can be a devastating diagnosis and unfortunately, there is no cure for the condition. However, patients should realise that there are many different types of treatments available and usually with combination of medical and surgical therapy the vast majority of patients can return to normal functioning.
What causes blepharospasm?
The causes of blepharospasm are complex. There is definitely a genetic predisposition which has been identified and many blepharospasm patients will report a family history of the condition. Most patients who develop blepharospasm hoe some history of chronic irritation of the eyes. This is usually in the form of blepharitis or dry eyes. It is thought that chronic eye irritation can induce a maladaptive reflex response, allowing the normal protective blinking reflex to assume a life of its own and overwhelm the normal functioning of the blink reflex. Our recent research at Moorfields has also shown that blepharospasm patients have an underlying abnormality in the nerve layer of the corneal epithelium and associated decreased sensitivity of the ocular surface. Similar sensory abnormalities have been identified in other dystonias, suggesting that decreased sensory stimulation to the brain can cause and input/output mismatch precipitating dystonia.
How is blepharospasm treated?
It is essential that blepharospasm is treated in a centre with significant expertise in the management of this condition. Moorfields Eye Hospital is a centre of excellence in the treatment of Blepharospasm with several hundred patients being actively treated.
The first step in treating blepharospasm is identifying and eliminating any cause for ocular surface irritation which can bring significant relief. You will initially have a full slit-lamp biomicroscope examination. Conditions causing irritation are usually euther dry-eye or blepharitis, but can also include Sjorgren’s syndrome, thyroid eye disease and herpetic keratopathy.
The mainstay of treatment is botulinum toxin . You will be examined carefully and the botulinum toxin injected into the overacting muscle groups. All patients will have different patterns of spasm and so the injection scheme is bespoke for different patients. Most patients will get significant relief from botulinum tocin therapy. In addition, if you are found to have a brow ptosis (droop), excess upper eyelid skin, or a droopy eyelid, this will usually need to be corrected surgically.
Is Botulinum toxin treatment safe?
The treatment is perfectly safe and there is no risk of developing botulism or food poisoning. There is no risk of development of general health problems after administration of botulinum toxin based on our experience at Moorfields of treating thousands of patients with blepharospasm over thirty years. There is no known risk when the treatment is given to women who are pregnant or breastfeeding, but some patients prefer to postpone treatment until they have given birth or weaned their children.
I have tried botulinum toxin, but it is not working, what else can I do?
Failure of treatment with botulinum toxin can occur either initially, or after many years of successful use. If botulinum toxin is not working there are many other approaches which include:
- Changing botulinum toxin type. There are new types of toxin that have been proven to be effective. These would include Xeomin and Neurobloc.
- Oral medications. There are several types of treatments which act directly of the brain and you may be asked to try these medications to determine if they are effective.
- Blepharoplasty surgery to remove excess upper eyelid skin and muscle
- Orbicularis myectomy involves the targeted removal of mucle fibres closest to the eyelid margin, this can have the effect of weakening the eyelid closure muscles.
- Brow suspension surgery is particularly effective for patients with apraxia of eyelid opening and involves internal suspension of the eyelid unit to the brow. This can be a very effective treatment in the appropriate patient group