Example of the muscle union procedure in a patient with a sixth cranial nerve palsy.

<p>(A) The muscles were approached using an approximately 160-degree limbal incision. (B) The superior rectus muscle was isolated. (C, D) A number of 5–0 nonabsorbable sutures were passed through approximately 1/3 to 1/2 of the width of the muscle belly at positions 8 mm and 6 mm posterior to the muscle insertions, without muscle splitting. (E) The inferior rectus muscle was isolated, and a number of 5–0 nonabsorbable sutures were placed in the same manner as in the superior rectus muscle. (F) The 5–0 nonabsorbable sutures that had been previously placed in the vertical rectus muscles were placed at positions 8 mm and 6 mm posterior to the muscle insertions of the lateral rectus muscle. (G, H) The first set of sutures at 8 mm posterior to the insertion was loosely tied to approximate the vertical rectus muscles near the lateral rectus muscle. Special care was taken to prevent unbalanced lateral rectus muscle displacement during the first tie. (I) The second set of sutures was tied 6 mm posterior to the insertion. Surgical assistants helped by pulling the vertical rectus muscles using forceps to ensure tight ties.