Efficacy and safety of botulinum toxin as a non-surgical option for upper eyelid retraction in active thyroid-associated ophthalmopathy: a prospective interventional study.

Aim: This study evaluates the efficacy and safety of botulinum toxin injection for the treatment of upper eyelid retraction in patients with active thyroid-associated ophthalmopathy (TAO).

Methods: A prospective interventional study was conducted on 30 patients diagnosed with upper eyelid retraction secondary to active TAO. Patients received a single transcutaneous injection of botulinum toxin (7.5 units) into the levator palpebrae superioris muscle. Outcomes were assessed in terms of marginal reflex distance-1 (MRD-1), vertical palpebral fissure height, and subjective symptom improvement was assessed at 1,4, and 12 weeks post-injection. Adverse effects were also recorded.

Results: The study demonstrated a significant reduction in MRD-1, with the peak effect observed between 2 and 4 weeks post-injection. The mean MRD 1 significantly reduced from 7.45 ± 1.76 mm at baseline to 4.43 ± 0.353 mm at 1 month (p < 0.001). Palpebral fissure height showed a similar trend. Improvement in ocular surface symptoms and photophobia was noted in 73.4% of patients. The effect began within 3-5 days post-injection, peaked by 1-2 weeks, and gradually waned over 2-3 months. The most common side effect was transient ptosis, which occurred in 13.3% of patients and resolved spontaneously. No serious adverse effects were observed.

Conclusion: Botulinum toxin A offers a safe, effective, and minimally invasive option for temporarily correcting upper eyelid retraction during the active phase of TAO, providing symptomatic relief during the active inflammatory phase. Given the contradictions for surgery in the active phase, this minimally invasive intervention serves as a valuable bridge therapy until surgical correction becomes appropriate.