Blepharospasm is a distressing condition, not to be confused with myokymia, the more common quivering of the eyelid. Defined as the ‘involuntary tight closure of the eyelids,’ blepharospasm can ease after several days or manifest as a chronic and life-altering muscle disorder. In a healthy eye, the blinking mechanism works to protect and clean and is only intermittently involuntary. In cases of chronic blepharospasm there is very little muscle control and difficulty in keeping the eye open, along with periods of excessive blinking. The abnormal twitch or spasm that causes the eyelid to clamp shut can be so unremitting the condition is officially recognised as a cause of sight-impairment. Associated pain can also be a problem with the muscular stress involved in trying to open the eye, along with the tension of the spasm itself, causing muscle pain down the face and neck. High sensitivity to bright light is also common in sufferers.
Blepharospasm is complex and without a specific known cause, however fatigue and ‘burnout’ are thought to be possible triggers, as are chemical and environmental irritants. It seems to run in families and often occurs in older people. Hormone Replacement Therapy and heavy benzodiazepine use can increase the risk, as can Multiple Sclerosis and some brain disorders or injuries involving the basal ganglia.
In the past the only available treatment options were tranquilisers or a myectomy – a radical surgical procedure whereby the blinking or winking muscles at the top of the eye are severed or removed. Botox, however, has revolutionised the treatment of blepharospasm – and was in fact developed for a similar purpose. It was while trialling Botox as a treatment for strabismus (or crossed eyes) that its cosmetic potential was discovered and this process of relaxing the eye muscles via targeted injection remains the same.
A thorough examination of the eye prior to Botox treatment should reveal the muscle or muscles in question. (When treatment is unsuccessful it is usually down to a failure to pinpoint the precise muscle, a situation which has improved in recent years.) Botox is then injected, cutting off the nerve signal and halting the muscle contraction, sometimes with immediate effect and sometimes over a period of one to two weeks. Injections are administered every three months and patients can usually resume their normal lives with a success rate of up to ninety percent. The effects wear off after two to three months, although repeated injections are well tolerated once the offending muscle is properly identified. Long term use can bring diminished efficacy, but dosage adjustments can safely compensate for this – the amount of Botox toxin required in this instance is relatively small.
Botox is used in a similar way to treat other facial muscle disorders such as hemifacial spasm and Bell’s Palsy. Possible side effects for facial Botox, all temporary, include blurred vision, drooping eyelids and headaches. Another is reduced facial expression along with the cosmetic benefits Botox is famous for such as smoothed eye lines and an unfurrowed brow.