[Botulinum therapy for acute esotropia]

To determine the effectiveness of the use of botulinum toxin type A in the treatment of acute esotropia in children.

A retrospective analysis of the results of using botulinum toxin type A in the treatment of acute convergent strabismus in 16 children was performed. Children's ages ranged from 3 to 15 years. Botulinum toxin was injected into the medial rectus muscles. In 6 patients with acute esotropia, botulinum toxin was injected into the internal rectus muscle of both eyes, in the rest of patients the toxin was injected into one eye. Two patients underwent chemodenervation of extraocular muscles twice. The injected dose of botulinum toxin (from 1 to 5 U) was chosen depending on the strabismus angle, the patient's age, and the duration of the disease. In order to form binocular vision, all patients underwent orthopto-diploptic treatment. The observation period lasted 12 to 18 months.

One month after chemodenervation, the orthoposition of the eyes was persistently restored in 7 children (43.75%). Esodeviation angle decreased steadily to 2 degrees in 4 patients (25%). A second injection of botulinum toxin was required to achieve orthotropy in 2 patients (12.5%) 4-6 months after chemodenervation. An increase of esodeviation angle was recorded in 3 patients (18.75%), which required classical surgical treatment of strabismus. One month after the injection, unstable binocular vision developed in 11 children (68.75%). After 1 year, binocular vision was successfully formed 13 patients (81.25%).

Chemodenervation in the majority of children with acute esotropia led to persistent orthoposition of the eyes. This created favorable conditions for the restoration of binocular vision during subsequent orthopto-diploptic treatment.