Symptomatic excyclotorsion following inferior transposition of both medial rectus muscles in patients with bilateral trochlear nerve palsy

PurposeTo report the development of a large degree of excyclotorsion following inferior transposition of the medial rectus muscles in 5 patients with bilateral acquired trochlear nerve palsies that had previously undergone bilateral modified Harada-Ito procedures.MethodsThe medical records of 5 patients who had undergone Harada-Ito procedure for bilateral trochlear nerve palsy between 2002 and 2010 and medial rectus muscle infraplacement surgery between 2004 and 2012 were retrospectively reviewed.ResultsAll 5 patients underwent a Fells-modified Harada-Ito procedure. All remained symptomatic due to a V pattern (eso- or exodeviation). Bilateral inferior transposition of the medial rectus muscles of either half or full tendon width was performed to alleviate this residual diplopia. The vertical transposition resulted in a symptomatic large degree of excyclotorsion (mean of 20°), which required reversal of the procedure.ConclusionsAfter inferior transposition of both medial rectus muscles in patients with bilateral superior oblique palsy who previously had bilateral modified Harada-Ito surgery, a large excyclotorsion (>20°) can occur. This can be managed by reversing the medial rectus transposition procedure.