The most common adverse effects of ocular botulinum toxin treatment are ptosis, lagophthalmos, dry eye, and induced vertical strabismus after horizontal muscle injection. These complications are usually temporary, resolving after several weeks. Rare complications include scleral perforation, retrobulbar hemorrhage, pupillary dilation, and permanent diplopia. Systemic botulism has been reported in animals and humans following massive injections of large muscle groups, but this has not been encountered in ophthalmologic use of botulinum toxin.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.