Muscle belly union surgery with or without medial rectus recession for the treatment of high myopic strabismus fixus.

PURPOSE To evaluate the results of surgery involving the union of the superior rectus muscle and the lateral rectus muscle with or without medial rectus recession (MRc) for the treatment of high myopic strabismus fixus over a 20-year period. METHODS The medical records of patients who underwent muscle belly union for the treatment of high myopic strabismus fixus were reviewed retrospectively. Patients were classified according to the timing of MRc. In group 1, MRc was performed before muscle union surgery; in group 2, MRc was performed concurrent with muscle union surgery; in group 3, MRc was not performed; in group 4, MRc was performed after muscle union surgery. RESULTS A total of 50 eyes of 40 patients were included. Mean esotropia decreased from 57.27Δ ± 25.45Δ (range, 8Δ-100Δ) before surgery to 11.67Δ ± 13.85Δ (range, -18Δ to 45Δ) after (P < 0.001); mean hypotropia, from 6.05Δ ± 9.13Δ (range, 0Δ-13Δ) before to 1.20Δ ± 3.03Δ (range, 0Δ-10Δ) after (P < 0.001). Mean abduction improved from -2.82 ± 1.17 (range, -4 to 0) before to -0.75 ± 0.92 (range, -3 to 0) after (P < 0.001); mean elevation, from -1.62 ± 1.62 (range, -4 to 0) before to -0.57 ± 0.90 (range, -3 to 0) after (P < 0.001). Preoperative esotropia and postoperative limitation in abduction were significantly lower in group 3 (P = 0.03; P = 0.01). CONCLUSIONS Muscle union surgery successfully corrected the restrictive esotropia and hypotropia. MRc in addition to muscle union surgery was not necessary for some patients, for whom preoperative esotropia was lower.