To describe a new surgical technique for treatment of complete third nerve palsy.

This study included patients with chronic complete third nerve palsy. The lateral rectus muscle (LR) 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 (MR) was sutured as posteriorly as possible from its insertion and cut. Next, the distal stump of the MR was split into two halves and united with the superior and inferior halves of the LR. Finally the proximal portion of the MR was sutured back to its original insertion. In cases with hypotropia and a functional superior oblique muscle (SO), SO tenectomy was also performed. Success was defined as postoperative horizontal deviation ≤10 PD and vertical deviation ≤5 PD.

Ten patients with mean age 32.4 ± 18.4 years were operated using this technique, two of them had prior 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 success rate was 70% and 90% for horizontal and vertical deviations respectively.

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.