[Electromyograph assistance and Mendonça's forceps--a comparison between two methods of botulinum toxin A injection...

To compare two methods of botulinum toxin A (BTA) injection into the extraocular muscle (EOM): the electromyographically (EMG) guided injection and the injection using Mendonça's forceps.

Twenty-nine (29) patients with strabismus and low visual acuity in one eye were examined at the Department of Ophthalmology of UNIFESP. They were divided into 2 groups -- group I with 17 patients receiving the botulinum toxin A injection using Mendonça's forceps, and group II with 12 patients receiving the toxin with electromyographical guidance. The patients of both groups were examined on the 7th and 14th day after intervention and the outcome of both methods of botulinum toxin A injection were compared. Friedman and Mann-Whitney correlation tests were used in the statistical analysis of the data.

Although the follow-up examinations on the 7th and 14th days showed a different behavior between both methods, there was no statistically significant difference between the mean values of the correction attained in both groups at the end of this study.

No statistically significant difference was shown between the two groups. Mendonça's forceps can be a safe alternative to electromyography to locate an extraocular muscle for botulinum toxin A injection.