Editing Botulinum toxin (section)

===Blepharospasm and strabismus===
{{See also|Botulinum toxin therapy of strabismus}}

University-based ophthalmologists in the US and Canada further refined the use of botulinum toxin as a therapeutic agent. By 1985, a scientific protocol of injection sites and dosage had been empirically determined for treatment of [[blepharospasm]] and strabismus.<ref>{{cite journal |vauthors = Flanders M, Tischler A, Wise J, Williams F, Beneish R, Auger N |title = Injection of type A botulinum toxin into extraocular muscles for correction of strabismus |journal = Canadian Journal of Ophthalmology. Journal Canadien d'Ophtalmologie |volume = 22 |issue = 4 |pages = 212–217 |date = June 1987 |pmid = 3607594 }}</ref> Side effects in treatment of this condition were deemed to be rare, mild and treatable.<ref>{{cite journal | vauthors =  | title = Botulinum toxin therapy of eye muscle disorders. Safety and effectiveness. American Academy of Ophthalmology | journal = Ophthalmology | volume = 96 | issue = Suppl 37-41 | pages = 37–41 | date = September 1989 | pmid = 2779991 | doi = 10.1016/s0161-6420(89)32989-7 }}</ref> The beneficial effects of the injection lasted only four to six months. Thus, blepharospasm patients required re-injection two or three times a year.<ref>{{cite journal |vauthors = Hellman A, Torres-Russotto D |title = Botulinum toxin in the management of blepharospasm: current evidence and recent developments |journal = Therapeutic Advances in Neurological Disorders |volume = 8 |issue = 2 |pages = 82–91 |date = March 2015 |pmid = 25922620 |pmc = 4356659 |doi = 10.1177/1756285614557475 }}</ref>

In 1986, Scott's micromanufacturer and distributor of Botox was no longer able to supply the drug because of an inability to obtain product liability insurance. People became desperate, as supplies of Botox were gradually consumed, forcing him to abandon people who would have been due for their next injection. For a period of four months, American blepharospasm patients had to arrange to have their injections performed by participating doctors at Canadian eye centers until the liability issues could be resolved.<ref name="Boffey_1986">{{Cite news |vauthors=Boffey PM |date=14 October 1986 |title=Loss Of Drug Relegates Many To Blindness Again |work=[[The New York Times]] |url=https://www.nytimes.com/1986/10/14/science/loss-of-drug-relegates-many-to-blindness-again.html |access-date=14 July 2010 |archive-date=26 January 2011 |archive-url=https://web.archive.org/web/20110126045116/http://www.nytimes.com/1986/10/14/science/loss-of-drug-relegates-many-to-blindness-again.html |url-status=live }}</ref>

In December 1989, Botox was approved by the US FDA for the treatment of strabismus, blepharospasm, and [[hemifacial spasm]] in people over 12 years old.<ref name=alg>{{cite web |date=30 April 2009 |title=Re: Docket No. FDA-2008-P-0061 |publisher=U.S. [[Food and Drug Administration]] (FDA) |url=https://www.fda.gov/downloads/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/UCM143989.pdf |access-date=26 July 2010 |archive-url=https://web.archive.org/web/20100706104512/https://www.fda.gov/downloads/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/UCM143989.pdf |archive-date=6 July 2010 |url-status=dead}} {{PD-notice}}</ref>

In the case of treatment of [[infantile esotropia]] in people younger than 12 years of age, several studies have yielded differing results.<ref name="Ocampo_2012">{{cite web |vauthors=Ocampo VV, Foster CS |url=http://emedicine.medscape.com/article/1198876-treatment#showall |title=Infantile Esotropia Treatment & Management |publisher=[[Medscape]] |date=30 May 2012 |access-date=6 April 2014 |archive-date=28 November 2014 |archive-url=https://web.archive.org/web/20141128091146/http://emedicine.medscape.com/article/1198876-treatment#showall |url-status=live }}</ref><ref>{{cite journal |vauthors = Koudsie S, Coste-Verdier V, Paya C, Chan H, Andrebe C, Pechmeja J, Leoni S, Korobelnik JF |title = [Long term outcomes of botulinum toxin injections in infantile esotropia] |journal = Journal Français d'Ophtalmologie |volume = 44 |issue = 4 |pages = 509–518 |date = April 2021 |pmid = 33632627 |doi = 10.1016/j.jfo.2020.07.023 |s2cid = 232058260 }}</ref>