Long-term outcomes of strabismus surgery in Mobius sequence

Purpose: Mobius sequence is a rare disorder that results from underdevelopment of the sixth and seventh cranial nerves, with subsequent facial weakness and impairment of ocular abduction. Approximately half of the affected patients have esotropia with limitation of extraocular movements. This study retrospectively reviews the long-term outcome of strabismus surgery for such patients. Methods: The long-term follow-up results in five children with Mobius sequence, who were observed after strabismus surgery for congenital esotropia, were analyzed. Results: All patients had a limitation of abduction in both eyes. Preoperative esotropia ranged from 20 to 30 prism diopters (PD) (mean 27 PD). Patient age at surgery ranged from 4.5 to 14 months. Bilateral medial rectus muscle recession was performed in all cases, ranging from 4.0 to 6.5 mm. Inferior transposition of the medial rectus muscles was performed in two patients for treatment of V-pattern, and two patients also had surgery for vertical strabismus. Follow-up ranged from 4 to 19.5 years (mean 11.7 years). The final horizontal alignment was <8 PD in all patients, and all demonstrated some binocularity. Conclusion: Bilateral medial rectus muscle recession is an effective treatment for esotropia associated with Mobius sequence, with good long-term stability.