A total of 27 children with esotropia (mean age, 3.9 years; range, 9 months to 13.8 years) were enrolled in a 9-month observational study following botulinum toxin A (BTX-A) injection of one (n = 7) or both (n = 20) medial rectus muscles. BTX-A dosage ranged from 3.0 to 6.0 units per muscle. Three participants developed tonic pupil, noted at the first follow-up visit, occurring 12-19 days after injection. All 3 cases occurred in the left eye of participants who underwent bilateral BTX-A injection by the same surgeon. Anisocoria diminished from a maximum of 4 mm at the 2-week visit to 1-2 mm in all patients over the 9-month postinjection data collection period. No adverse visual outcomes were noted. Tonic pupil is an infrequently reported complication of BTX-A injection for strabismus. The experience of our investigator group suggests the need for careful injection technique and thorough preinjection counseling.
Bibliographical noteFunding Information:
The authors thank Yusuf Sevim, MD, for his assistance in the writing of this article. Supported by National Eye Institute of National Institutes of Health, Department of Health and Human Services EY011751, EY018810, and EY023198. The funding organization had no role in the design or conduct of this research.
Supported by National Eye Institute of National Institutes of Health , Department of Health and Human Services EY011751 , EY018810 , and EY023198 . The funding organization had no role in the design or conduct of this research.
© 2016 American Association for Pediatric Ophthalmology and Strabismus.