[Is bimedial muscle belting an alternative procedure to retro-equatorial myopexy in convergence excess esotropia?].

OBJECTIVE: Retro-equatorial myopexy is a standard procedure to reduce convergence excess esotropia and esotropia with variable deviations. However, the surgical effect of the faden operation can be accompanied by restricted eye motility in side-gaze. Revision of the operated muscle is often difficult due to scarring of the muscle and adhesions with the sclera. Bimedial muscle belting is an alternative procedure that tries to reduce these side effects.
METHODS: The surgical technique, which consists of bridging the medial rectus with a silicon band sutured to the sclera, has been demonstrated previously. Results after bimedial muscle belting were analyzed in 33 patients retrospectively after 6 weeks and 37 months, and compared with the results after the faden operation.
RESULTS: Angles at distance were reduced 6 weeks postoperatively by a median value of 6.0 degrees and for near by a median of 10.5 degrees , which is very similar to the effect seen after the faden operation. After 37 months, results remained stable with a reduction of a median of 6.0 degrees at distance and 10.0 degrees for near. Significant incomitance in side-gaze was only rarely noted after muscle belting (maximum 5 degrees ), whereas it was seen frequently after the faden operation, 4.0 degrees -6.6 degrees (maximum 9 degrees ).
CONCLUSIONS: Bimedial rectus belting is an alternative procedure to the faden operation, yielding similar results. Surgically, the procedure is more demanding, as the fixating sutures have to be passed through the sclera twice on either side. However, the integrity of the muscle is maintained and major adhesions with the sclera do not develop. Thus, the muscle can be subjected to recess or resect surgery without touching the anchoring of the belt in the sclera. In addition, revision surgery can be carried out easily with the belt left in place.