Evaluation of the therapeutic use of botulinum toxin A in the periorbital region

Abstract

Botulinum toxin blocks acetylcholine release at the neuromuscular junction causing paralysis that is reversed within 4 months. The toxin was well known for its lethal effect when ingested with food (botulism); however, it was found to be highly effective in various disorders, both cosmetic and noncosmetic. The therapeutic uses in ophthalmology include treatment of strabismus, spastic focal facial dystonias, induction of temporary ptosis in cases of lagophthalmos (chemotarsorrhaphy), temporary correction of dysthyroid upper eyelid retraction, suppression of lacrimal gland secretion to temporarily control gustatory lacrimation, some cases of obstructive epiphora and primary hyperlacrimation, and temporary correction of lower lid entropion. In this prospective study, we evaluate the results of using botulinum toxin A (botox) injection in some periorbital pathologies namely, focal facial dystonias, lower lid entropion, lagophthalmos, and epiphora. Fifty patients were treated with botox (20 patients with focal facial dystonias, nine with lagophthalmos, eight with lower lid entropion, and 13 with epiphora), different techniques were used according to the pre-existing pathology, and the following data were recorded: age and sex, total dose for each injection, onset and duration of effect, degree of improvement, and the occurrence of any adverse effects. The study results supported the high efficacy of botulinum toxin for treatment of blepharospasm, hemifacial spasm, lagophthalmos, lower lid entropion, and epiphora, with marked to moderate improvement in 99, 87.5, 55.5, 75, and 92.3% of patients, respectively. Few side effects occurred but they resolved spontaneously without residues. We concluded that botulinum toxin A is a safe and effective treatment with a temporary outcome that may be desirable in certain situations.