Effect of Botulinum Toxin Type a Chemodenervation in Esotropia

ABSTRACT

PURPOSE: To investigate the efficacy of botulinum toxin type A chemodenervation in various types of esotropia(ET). METHODS: Enrolled eleven esotropic patients treated with botulinum toxin type A and examined the amount of esotropic correction and success rate of less than 10 PD (prism diopter) of postinjection deviation at 5 months after injection. RESULTS: Among the eleven esotropic patients, there were 7 cases of infantile ET, 2 cases of partially accommodative ET and 2 cases of basic ET. The mean preinjection deviation was 30.5 +/- 7.3 PD. The amount of correction was 17.7 +/- 4.3 PD and correction rate of deviation was 57.5%. In 6 of 11 cases, the postinjection deviation was within 10 PD and therefore success rate was 54.5%. In 5 patients (45.5%), their ET was undercorrected. In patients with under 20 PD of preinjection deviation, success rate was 75% (3/4) and those with over 20PD, the rate was 42.9% (3/7). In partially accommodative ET, 2 (100%) of 2 cases were aligned within 10PD. CONCLUSIONS: In comitant ET, botulinum toxin chemodenervation shows high undercorrection rate. The effects of botulinum toxin type A chemodenervation were better for relatively small angle and in partially accommodative ET than nonaccommodative one. But further study with more cases is needed.