Botulinum toxin is a protein and neurotoxin produced by the bacterium Clostridium botulinum. In the early 1980s, university-based ophthalmologists in the USA and Canada further refined the use of botulinum toxin as a therapeutic. agent. In December 1989, Botox, manufactured by Allergan, Inc., was approved by the US Food and Drug Administration (FDA) for the treatment of strabismus, blepharospasm, and hemifacial spasm in patients over 12 years old. There are two kinds of botulinum in the Iirsh market Dysport (Azzalure) and Botox (Vistabel).