Specificity of using botulinic toxin type A for blepharospasm treatment

Abstract

Blepharospasm (BS) is one of the diseases characterized exclusively by involuntary face movements (facial hyperkinesis). Typical clinical manifestations include squinting or increased blinking. Among frequent patients’ complains at the disease onset are unpleasant irritations, a foreign body sensation, itching, dry eyes, and frequent blinking. Dynamism is a typical BS feature: 1) it increases during emotional stress, in stressful situations, during fatigue, eye strain (reading), in bright light; 2) disappears while sleeping; 3) decreases after waking up; 4) «corrective gestures», such as touching skin of the eyelids, paraorbital regions and glabellar region, wearing glasses, chewing or absorbing sweets, other arbitrary movements, affect BS. Botulinum therapy (botulinum toxin type A (BtA) injections, in particular using Relatox, the effectiveness of which has been demonstrated in clinical studies) is considered the «gold standard» in BS treatment. BtA is injected mainly into the orbicular muscle of eye, superficially, into the upper, lower eyelids and outer eye corner. The clinical effect occurs quickly, already in the first week after injection and lasts 3 months or more. Cases of botulinum therapy inefficiency in treating BS and other facial hyperkinesis are extremely rare.The article describes BS main clinical aspects, BtA injection schemes as well as adverse events during the therapy. Electromyography is not mandatory to assess BtA effectiveness in BS treatment, but it is necessary in cases of inefficient therapy, adverse events or the therapy complications. It is particularly important to strictly comply with recommended BtA doses, and that the drug is injected by a certified specialist only. Botulinum therapy for BS patients is a highly effective and, in most cases, the only treatment with a good safety profile.