Botulinum Toxin for Strabismus
Botulinum toxin type A (BoNT-A) injection into extraocular muscles as a minimally invasive alternative or adjunct to strabismus surgery. One of the most actively studied modern therapies for acute-acquired-concomitant-esotropia. 1
Mechanism
Injection into the medial rectus muscles produces temporary chemodenervation — reducing convergence tone and allowing the eye position to drift outward. This window of altered alignment may permit binocular fusion to re-establish before chronic motor adaptation sets in.
Advantages Over Surgery
- Minimally invasive, office-based procedure
- Faster recovery
- Avoids surgical scarring (preserving future surgical options)
- Particularly useful in children and fluctuating cases
- Growing interest in early intervention before chronic motor adaptation develops
Clinical Evidence
Recent studies report:
- Significant improvement in ocular alignment
- Recovery of stereopsis
- Good patient satisfaction
- Comparable outcomes to surgery in selected patients 1
Limitations
- Temporary effect (requires repeat injections or eventual surgery in some cases)
- Risk of ptosis or vertical deviation
- Less predictable than surgery for large deviations
- Not universally available