The Muscles around the eyelid can be affected by a wide range of movement disorders. The most common of these are Benign Essential Blepharospasm and Hemifacial Spasm. Blepharospasm is a disabling condition affecting the eyelids but also other facial muscles. Rarely, the tongue, mouth and neck are also affected. Blepharospasm is always profoundly disabling with a significant impact on vision.
The cause of blepharospasm remains unknown but it is thought to arise from a combination of genetic susceptibility, chronically irritable eyes and abnormalities in the way that the blink reflex is processed by the brain. The mainstay of treatment for blepharospasm is to firstly alleviate the cause of ocular irritation and secondly to use botulinum toxin to weaken the muscles around the eyes. Botulinum toxin is usually highly effective and reducing symptoms, but in a small number of cases, surgery can also be of benefit in combination with botulinum toxin. Removal of eyelid muscle and also eyelid suspension techniques all have a role to play in the management of blepharospasm.
Hemifacial spasm affects one half of the face and is usually due to irritation of the nerve that controls this muscle. Hemifacial spasm is also treated with botulinum toxin to the affected areas which commonly requires injections around the eye, mouth and neck areas.
Patients with facial nerve paralysis can also benefit form botulinum toxin. This can alleviate and twitching caused by misfiring of the nerve - often called 'aberrant innervation'. Botulinum toxin can also be extremely effective in restoring or improving facial symmetry by careful targeting overactive muscles of the face.
It is not uncommon for patients on long-term botulinum toxin therapy to develop resistance to the drug, making it less effective with time. Mr Ezra uses a comprehensive range of botulinum toxin preparations, all subtly different, to ensure that different formulations can be used to overcome resistance to a particular drug. Mr. Ezra is the clinical lead for the botulinum toxin service at Moorfields and has extensive experience at treating these conditions.