Efficacy of Botulinum Toxin A injection in treatment of Congenital Esotropia

Backgroud and Congenital esotropia is one of most common ocular disorder in children with genetic origin. Amblyopia، decreased streopsis and cosmetic problems are its complication that affect person''s fate in terms of career psychological issues. The aim of this study was to determine the effect of botulinum toxin A (Dysport) injection in subconjunctival space near medial rectus insertion of both eyes for treatment of congenital esotropia. Subjects and Thirty babies (aged 6-54 months) with congenital esotropia who were otherwise systemically and neurologically normal were enrolled in this study. Ten units of toxin (Dysport) were injected (under sedation) into the subconjunctival space near medial rectus insertion of both eyes. The angle of deviation was measured six times: after 3 days، 1 week، 1، 3، 6 and 12 months after injection. Twelve months after injection، angle of deviation decreased from 52 ± 17 PD to 27. 8 ± 21. 29 PD in 86. 3% of patients. Success of treatment achieved in 23. 3% of patients (P=0. 008). In seventeen cases (56. 6%) with angle of deviation≤ 45 PD (before injection) improvement was better (p=0. 030)، 41. 1% of this group after 1 month، 70% after 3 months، 76% after 6 months، and 41. 1% after 12 months follow up achieved orthophoria. Botulinum toxin A injection into subconjunctival space near medial rectus insertion is a safe method that is not only effective transiently for eye alignment but also can reduce total deviation. Long term improvement seems to be achievable in cases with small angle deviation (equal or less than of 45 PD).