Tetracaine Eye Drops as a Preemptive Topical Skin Anesthesia for Botulinum Toxin Type A Injections in Blepharospasm...

To evaluate the efficacy and safety of topical tetracaine eye drops as a preemptive skin anesthetic during botulinum toxin type A injection in blepharospasm patients.

A double-blind, split-face randomized controlled trial was conducted in 17 participants diagnosed with benign essential blepharospasm between November 2023 and July 2024. Each patient received randomized treatment on opposite sides of the face: a cotton pad soaked with 5 mL of 0.5% tetracaine ophthalmic solution on one side and normal saline solution on the other, for 30 minutes. The cotton pad temperature, the injection dose, and the techniques were controlled on each side. A single neuro-ophthalmologist performed the injection. Pain scores were immediately rated after the injection, using a numeric rating scale from 0 to 10. Jankovic rating scale and complications were assessed on the day of injection, then 1 month and 3 months after injection.

The numeric rating scale on the side receiving topical 0.5% tetracaine eye drops was significantly lower than the side receiving topical normal saline solution (4.56 ± 2.63 vs 6.71 ± 2.54, p = 0.013). There were no significant differences in the Jankovic rating scale, cotton pad temperature, bleeding at the injection site, and other complications between the two groups.

The application of 0.5% tetracaine ophthalmic solution as a preemptive topical skin anesthesia can decrease pain during botulinum toxin type A injection for blepharospasm patients without affecting the efficacy or producing any significant complications.