Clinical Ophthalmology (Jan 2021)
The Efficacy of Dose Increments of Botulinum Toxin A in the Treatment of Childhood Esotropia
Abstract
Fatemah T Alshamlan, Halla A Al Abdulhadi, Mofi M Alwalmany, Khalid S Alotaibi Pediatric Ophthalmology and Strabismus Department, Dhahran Eye Specialist Hospital, Dhahran, Saudi ArabiaCorrespondence: Fatemah T AlshamlanPediatric Ophthalmology and Strabismus Department, Dhahran Eye Specialist Hospital, P.O. Box 39301, Dhahran 31942, Saudi ArabiaEmail [email protected]: Botulinum toxin is known to have a powerful chemodenervation effect, and it is a well-established alternative to incisional surgery for strabismus. This study aims to investigate the efficacy of dose increments of botulinum toxin A (BTA) for the treatment of specific ranges of angle deviation.Methods: This was a prospective study that included patients presenting with esotropia to Dhahran Eye Specialist Hospital between 2016 and 2020, who were managed by a single surgeon. Botulinum toxin was given in different dosages (2.5, 5, 7.5, 10 international units (IU)) according to the size of deviation (11– 19, 20– 29, 30– 39, and ≥ 40 prism diopters (PD)), respectively. A successful outcome was defined as deviation ≤ 10 PD in the last visit (a minimum of 6 months) following a single injection.Results: A total of 56 patients with esotropia were included. The mean pre-treatment angle of deviation was 38.6 ± 2.5 PD. BTA injection in a dose of 2.5 IU for the 11– 19 PD angle of deviation showed the highest rate of successful outcomes (75%). According to the type of esotropia, partially accommodative esotropia showed the best response to the use of dose increments (59%). The incidence of ptosis post-BTA injection was the least (37.5%) with the smallest dose (2.5 IU).Conclusion: BTA usage in dose increments is safe, efficient, and might be more cost-effective with less incidence of BTA associated complications. Different esotropia diagnoses have different clinical responses. However, larger studies are necessary to better predict the outcome of using dose increments.Keywords: esotropia, botulinum toxin A, angle of deviation
