Yamada's surgery for treatment of myopic strabismus fixus.

PURPOSE: Myopic strabismus fixus is characterized by acquired progressive esotropia and hypotropia associated with restricted elevation and abduction. Treatment is difficult, with recurrence of the large-angle esotropia even after surgery. The aim of this study was to describe two cases of myopic strabismus fixus successfully treated with Yamada's surgical technique.

METHODS: Two patients with myopic strabismus fixus were submitted to hemitransposition of the superior rectus (SR) and lateral rectus (LR) muscles with scleral fixation at 7 mm from the limbus. In one patient, the hemitransposition was associated with ipsilateral MR muscle recess as described by Yamada, while in the other, botox injection into the MR muscle was performed. In both cases Yamada's procedure was associated with 4 mm resection of the hemitransposed portions of the SR and LR muscles to increase the muscular tonus and then improve surgical effects.

RESULTS: The patient submitted to the MR recess presented with satisfactory ocular alignment after 6 months postoperative. The other patient submitted to botox injection at the MR muscle presented recurrent esotropia after 3 months. RM recess was then performed and an excellent ocular alignment was achieved.

CONCLUSIONS: Yamada's surgical technique can provide acceptable ocular alignment in cases of myopic strabismus fixus. The surgical effects can be potentialized with resection of the hemitransposed portions of the SR and LR muscles. In addition, we demonstrated that botulinum toxin injection at the RM muscle is not an effective treatment in these cases.