Autogenous Fascia Lata Graft Fixation to Treat Exotropia Resulting From Iatrogenic Medial Rectus Transection

Purpose: To describe autogenous fascia lata graft fixation as a novel method to treat exotropia related to medial rectus (MR) muscle injury following functional endoscopic sinus surgery. Methods: Three consecutive patients with MR transection and exotropia after functional endoscopic sinus surgery were selected. Preoperative examination was performed; no MR function was noted for over 3 months after injury. CT and dynamic functional MRI were performed, where MR transection and medial wall breach were noted. An autogenous fascia lata graft was harvested and fixated from the remaining periosteum of the posterior-most extent of the medial orbital wall and attached to the globe at the MR insertion. In addition, an ipsilateral lateral rectus muscle recession was performed. Results: Alignment of the eyes in primary gaze and downgaze was achieved and remained so at the 3-month postoperative examinations, with minimal head turn or prism correction (<5 prism diopters) necessary to control diplopia. Two patients required recession of the fascial graft for a minor overcorrection and have remained stable for over 6 months. Conclusions: Severe exotropia secondary to MR damage following functional endoscopic sinus surgery is a known complication historically difficult to treat. Traditional surgical methods, including vertical muscle transposition, commonly result in complete recurrence of exotropia and increase risk of anterior ocular ischemia. Unlike simple nonabsorbable suture fixation, fascial grafts are completely biointegratable, do not result in significant inflammation, and are unlikely to rupture. Fascia lata graft fixation of the MR to the posterior orbital medial wall is a new and successful method to eliminate exotropia after MR injury.