Silicone band loop myopexy in the treatment of myopic strabismus fixus
Reviewed by Jonathan Chan

This is a retrospective case series of chart review of patients who had silicone band loop myopexy between January 2008 to December 2012 for myopic strabismus fixus (MSF) at a tertiary eye centre in India. A minimum period of two months follow-up after surgery was required for inclusion, and patients who had previous incomplete details or preoperative alignment were excluded. The main outcome measures include alignment postoperatively, improvement in extraocular motility postoperatively, and intraoperative and posterior complications. The surgical procedure was performed under general anaesthetic and intraoperative forced duction test was performed in order to assess the tightness of each of the rectus muscles. A fornix base conjunctival incision was placed in the superotemporal quadrant approximately 10 to 12mm from the limbus. The lateral rectus and the superior rectus muscles were hooked and isolated and both were examined intraoperatively. A scleral tunnel of 3 to 4mm in length was constructed 14 to 16mm from the limbus in between the bellies of the superior rectus and lateral rectus using a hockey J stick buckle blade. A type 240 silicone band was then passed under the lateral rectus and through the scleral tunnel and the superior rectus. The two ends were then passed through a Watzke sleeve and tightened to bring the bellies of the superior rectus and lateral rectus together by pulling the two ends in opposite direction. The conjunctiva was closed with interrupted sutures using an 8-0 non-absorbable monofilament nylon suture. Forced duction test was repeated to look for the tightness and a medial rectus recession was performed if the medial rectus tightness was found to be significant. A total of 26 eyes of 15 patients had surgery at the mean age of 27.8±16.4 years (range 7-72 years). A mean follow-up was 7.9±8.4 months (range 2-28 months, and median of four months). Eleven patients had bilateral loop myopexy where four patients underwent unilateral loop myopexy. Sixteen eyes underwent additional medial rectus recession between a range of 5-7.5 mm. At the last follow-up, the mean abduction limitation improved to -1.5±1.3 from -2.9±1.2, P=0.0; mean elevation limitation improved to -1.2±0.9 from -2.8±1.1, P=0.0; mean esotropia improved to 16.9±17.4 PD from 79.3±32.3PD, P=0.0; success was defined as deviation less than 20 PD, was achieved in 73%. Mean hypotropia at presentation was 8.9±10.1 PD, which improved to 0.6±1.3 PD, P=0.007. Foreign body sensation was reported by two patients (three eyes) and a silicone band removal was performed in two eyes of one patient five months postoperatively. The patient maintained alignment 24 months postoperatively. The authors concluded that a modified fixated silicone band loop myopexy with or without medial rectus recession is a safe and effective procedure in the management of MSF and improves alignment significantly. Further studies particularly those comparing suture silicone band loop myopexy looking at the anterior ciliary circulation and muscle related complications are required.

Silicone band loop myopexy in the treatment of myopic strabismus fixus: surgical outcome of a novel modification.
Shenoy BH, Sachdeva V, Kekunnaya R.
BRITISH JOURNAL OF OPHTHALMOLOGY
2015;99:36-40.