Partial rectus muscle–augmented transpositions in abduction deficiency

Abstract Purpose Lateral posterior fixation sutures increase the effect of full rectus extraocular muscle transpositions. Partial rectus muscle transposition may be indicated to minimize the risk of anterior ischemia when multiple rectus muscles require surgery to achieve ocular alignment. Purpose To report a modification of full vertical rectus muscle transposition with lateral posterior fixation sutures for use in patients at risk for anterior segment ischemia. Methods Ten cases of unilateral split rectus muscle transposition augmented with lateral posterior fixation sutures were analyzed. Five patients had Duane's syndrome with esotropia in primary position, and five patients had sixth-nerve palsy. Results Seven patients had a history of ipsilateral rectus muscle surgery, and three patients underwent simultaneous surgery on ipsilateral horizontal rectus muscles. In Duane's syndrome patients, the preoperative angle of deviation at distance was 15.8 ± 5.8 prism diopters (PD) (range, 10 to 25) compared with 3.2 ± 4.4 PD (range, 0 to 8) postoperatively ( P = .005). In patients with sixth-nerve palsy, the preoperative angle of deviation at distance was 45.2 ± 23.9 PD (range, 16 to 80) compared with −5 ± 14.1 PD (range, −30 to 5) postoperatively ( P = .004). Postoperative binocular single visual fields enlarged in seven of seven patients. Conclusion Partial rectus muscle–augmented transposition allows surgery on multiple ipsilateral rectus muscles in (1) Duane's syndrome patients with esotropia, marked cocontraction, and/or limitation to both horizontal rotations and in (2) sixth-nerve palsy patients with ipsilateral medial rectus tightness. Augmented partial rectus muscle transpositions improve ocular alignment and may enlarge binocular single fields in patients with persistent deviations despite previous muscle surgery.