Lateral Rectus-Medial Rectus :union: Surgery: A New Surgical Technique for Treatment of Total Third Nerve Palsy

To describe a new surgical technique for treatment of total third nerve palsy. This study was conducted in the form of interventional and prospective. Patients with chronic third nerve palsy were included. In this procedure, lateral rectus muscle (LR) was splitted as posteriorly as possible; then, superior and inferior halves disinserted and passed between the sclera and superior and inferior rectus muscles respectively, medial rectus muscle (MR) was sutured as posterior as possible from insertion and cut, then residual distal stump of MR was splitted into two halves and sutured to superior and inferior halves of LR, and proximal portion of MR was sutured back to its insertion. When there were hypotropia and functional superior oblique muscle (SO), tenectomy was also added. For the first day after operation, globe was fixated in adduction position with traction suture. Horizontal and vertical deviation changes were evaluated before and at least 3 months after surgery. The success was defined as postoperative horizontal deviation ≤10 PD and vertical deviation≤5 PD. After at least 3 months of follow-up, if the Bell's reflex was acceptable, ptosis surgery was also performed, otherwise crutch glasses was prescribed. Ten patients were operated by this method. The mean age of the patients was 32.4 ± 18.4 years (range 759) years. Two of them had history of previous horizontal recession-resection surgery and one of them had a history of surgery on the upper right muscle of the same eye. Mean preoperative exotropia was 84±14.9 (45 to 100) PD that reduced to 6±8.4 (0 to 20) PD (P<0.001) at 3months and 6.5±8.2 (0 to 20) PD (P<0.001) at the last examination. The mean vertical deviation was 16.5±10 (0 to 30) PD that reduced to 3±4.8 (0 to 15) PD (p=0.001) at 3months and 2.5±3.5 (0 to 10) PD (p=0.001) at the last examination. Mean follow-up duration was 13.2±7.9 (5.1 to 29.6) months; success rate was 70 % and 90 % for horizontal and vertical deviation, respectively. Two cases (20%) required additional strabismus surgery. Lateral rectus-medial rectus :union: technique is an effective and long-lasting procedure to overcome large angle exotropia of total third nerve palsy. This method can also be used as a reoperation surgery.