Unaugmented Vertical Muscle Transposition Surgery for Chronic Sixth Nerve Paralysis

Introduction: Chronic sixth nerve palsy can cause incapacitating diplopia requiring vertical muscle transposition surgery. Augmentation of surgery, with lateral fixation sutures, medial rectus recession or botulinum toxin injection, is associated with an increased risk of complications. Purpose: Our aim was to evaluate the efficacy and safety of unaugmented full-tendon vertical rectus transposition in chronic sixth nerve paralysis. Methods:Longitudinal study of 21 patients with chronic sixth nerve paralysis of longer than 6 months duration, who underwent superior and inferior recti transposition surgery without medial rectus recession or botulinum toxin injection. Details of surgery, preoperative and postoperative examinations including full orthoptic examination were obtained from an electronic database. Outcomes included the change in angle of deviation, the requirement for further surgery to the medial rectus and postoperative improvement in diplopia. SPSS software (Version 12.0.1, SPSS Inc. Chicago, I...