Lateral Rectus–Medial Rectus Union: A New Surgical Technique for Treatment of Complete Third Nerve Palsy

Purpose: To describe a new surgical technique for the treatment of complete third nerve palsy. Methods: This study included patients with chronic complete third nerve palsy. The lateral rectus muscle was split, followed by disinsertion of the superior and inferior halves, which were passed between the sclera and superior and inferior rectus muscles, respectively. Then the medial rectus muscle was sutured as posteriorly as possible from its insertion and cut. Next, the distal stump of the medial rectus muscle was split into two halves and united with the superior and inferior halves of the lateral rectus muscle. Finally, the proximal portion of the medial rectus muscle was sutured back to its original insertion. In cases with hypotropia and a functional superior oblique muscle, superior oblique tenectomy was also performed. Success was defined as postoperative horizontal deviation of 10 prism diopters (PD) or less and vertical deviation of 5 PD or less. Results: Ten patients with a mean age of 32.4 ± 18.4 years had surgery using this technique; 2 of them had a history of strabismus surgery. Mean exotropia was 84 ± 14.9 PD, which reduced to 6.5 ± 8.2 PD. Mean vertical deviation was 16.5 ± 10 PD, which reduced to 2.5 ± 3.5 PD. Mean follow-up was 13.2 ± 7.9 months, and the success rate was 70% and 90% for horizontal and vertical deviations, respectively. Conclusions: The lateral rectus–medial rectus union technique is an effective and long-lasting procedure to overcome large-angle exotropia associated with complete third nerve palsy. This method can also be employed as a reoperation procedure. [ J Pediatr Ophthalmol Strabismus . 2019;56(1):10–18.]