Background: Although the use of endoscopes and image guidance provide some safeguards, motility complications from orbital injury during endoscopic sinus surgery still pose a significant concern and can provide a therapeutic challenge.
Methods: We present the case of a 40-year-old woman with strabismus secondary to an iatrogenic injury to the medial rectus muscle during endoscopic sinus surgery.
Results: Permanent resolution of diplopia was achieved with botulinum toxin A injection into the lateral rectus muscle without the need for surgical intervention.
Conclusion: Botulinum toxin A should be considered as a first-line early therapeutic option for cases of iatrogenically induced strabismus after endoscopic sinus surgery when complete transection or entrapment is not present.