Vertical Muscle Transposition with Augmentation for Treatment of Exotropia Caused by Iatrogenic Lost Medial Rectus Muscle

Purpose: To evaluate the results of vertical muscle transposition with augmentation in cases of exotropia caused by iatrogenic lost medial rectus muscle. Methods: This is a retrospective review of 5 cases of lost medial rectus with exotropia and marked limitation of adduction that underwent surgery. All cases had a history of strabismus surgery on the medial rectus and failed attempt at retrieval of the lost muscle. Results: Five patients fulfilled the criteria. Full tendon vertical muscle transposition with augmentation sutures was done for all cases. Surgery led to a significant reduction of the angle of exotropia 25.8±13.6 ?D (P=0.027) and improvement in adduction of 7.5±3.8 degrees (P=0.034). There were no complications. Conclusions: Isolated vertical muscle transposition with augmentation is a useful option to improve the exotropia and adduction deficit in patients with iatrogenic lost medial rectus muscle