Ophthalmologists specializing in eye muscle disorders (strabismus) had developed the method of EMG-guided injection (using the electromyogram, the electrical signal from an activated muscle, to guide injection) of local anesthetics as a diagnostic technique for evaluating an individual muscle’s contribution to an eye movement. Because strabismus surgery frequently needed repeating, a search was undertaken for non-surgical, injection treatments using various anesthetics, alcohols, enzymes, enzyme blockers, and snake neurotoxins. Finally, inspired by Daniel Drachman’s work with chicks at Johns Hopkins, Alan B Scott and colleagues injected botulinum toxin into monkey extraocular muscles. The result was remarkable: a few picograms induced paralysis that was confined to the target muscle, long in duration, and without side-effects.
Botox only lasts three to six months—and yet what's less commonly discussed is this: Facial muscles naturally weaken over time and going overboard in a certain area could have unwanted consequences. "If you do too much Botox on your forehead for many, many years, the muscles will get weaker and flatter," cautions Wexler, adding that the skin can also appear thinner and looser. Moreover, as your muscles become weaker, they can start to recruit surrounding muscles when you make facial expressions. "If one stops using their forehead muscles, they may start squinting using their nose and have wrinkles along the side of their nose," she explains. Translation: You need even more Botox for the newly recruited muscles, says Wexler. To avoid these kind of missteps, researching a doctor diligently is essential, as is approaching injectables conservatively, and asking questions about how the treatment will be tailored to your needs.
Tell your doctor if you have received any other botulinum toxin product in the last 4 months; have received injections of botulinum toxin such as Myobloc®, Dysport®, or Xeomin® in the past (tell your doctor exactly which product you received); have recently received an antibiotic by injection; take muscle relaxants; take an allergy or cold medicine; take a sleep medicine; take aspirin-like products or blood thinners.