Botulinum toxin is a protein product of the gram-negative anaerobic bacterium, Clostridium botulinum, it also contains the same toxin found in food poisoning. After purification, botulinum toxin became the first bacterial toxin to be used in medical treatments. (5 Vangelova) After being injected into the body, the toxin attaches itself to nerve endings at the point where the nerves join muscles. The chemical acetylcholine is released which then signals the muscles to contract resulting in weakness and paralysis. Extra contractions are blocked by the injections into the muscle but leave enough strength for normal use. (Vangelova) This botulism toxin is categorized into 7 serotypes (A though G). Type A of botulism toxin is most commonly known as Botox. The Botox toxin is recognized as the most potent and has been studied the most for clinical use. Although botulinum toxin is a lethal toxin, it can be used as an effective and powerful medication by injecting minimum quantities of the toxin into overactive muscles. (Shipla) In 2002, Botulinum type A was approved and has since become a popular cosmetic treatment to help minimize the appearance of facial lines and wrinkles, along with the smoothing of skin for a younger appearance. (Botox: Beyond Cosmetic Fixes) The use of this type A Botulinum toxin is rapidly expanding to include a variety of treatments including ophthalmological disorders, gastrointestinal, urological, orthopedic, dermatological, secretory, painful and cosmetic disorders. (Jankovic)
Botulinum toxin first gained clinical acceptance as a result of marked benefits it produced in patients with dystonia. This neurological disease involves chronic abnormal muscle posture and tension. (5 Vangelova) Dystonias are classified by the body part they affect or as syndromes based on their patterns. The most common type is cervical dystonia which affects the neck muscles. Oromandibular dystonia causes spasms of the jaw, lips, and tongue muscles. Spasmodic dystonia affects the throat muscles that are responsible for speech. Tardive dystonia is caused by a reaction to a drug. Blepharospasm is a type of dystonia that affects the eyes, and is the one that will be discussed in the next paragraph.
Blepharospasm is an incapacitating condition that can cause functional optical blindness. Involuntary activity of the optical muscles leaves patients with symptoms such as lower facial spasms and/or oromandibular spasm. The use of botulinum toxin in treating blepharospasm was FDA approved in 1989, but was already being used since 1982. It is now the choice of treatment by many ophthalmologists and patients as well. Injections should be delivered inside the orbital rim to achieve optimal results. There are possible side effects that could be detrimental to the patients’ vision if the erroneous ocular muscle is injected. Moderate or marked improvement has been reported in more than 90% of patients with blepharospasm injected into the orbicularis oculi...