RESUMO
BACKGROUND: Congenital esotropia is the most frequent type of strabismus. Botulinum toxin is a treatment option with variable results. We undertook this study to determine the frequency and associated factors with consecutive permanent esotropia in patients diagnosed with congenital esotropia treated with botulinum toxin. METHODS: A retrospective review was achieved in patients with congenital esotropia treated with botulinum toxin and who remained in esotropia after a minimal follow-up of 6 months. Pre- and postnatal background, cycloplejia, magnitude of the pre-application deviation, injected dose and number of applications were analyzed. RESULTS: A total of 84 patients were included. Of all patients,12 (14.28%) remained in consecutive esotropia (six males and six females). Age range was from 5 months to 2 years (average: 10.75 months). Initial esotropia ranged from 20-50 prism diopters (PD) with an average of 37.9 ± 9.64 PD. One patient had variability in the magnitude of the deviation prior to treatment. During the maximum follow-up, the magnitude of the esotropia was from 10 to 40 (average, SD 18 ± 8.01 PD). In five subjects a variability was observed in the magnitude of the angle of deviation by a range of 10-40 PD, and in seven subjects the deviation was stable with an average of 20 PD. Eleven subjects had some degree of psychomotor delay (91.66%) and one subject had a non-significant history. CONCLUSIONS: In patients with consecutive permanent esotropia after application of botulinum toxin, the most prevalent characteristic is neurological.