Inferior rectus muscle contracture syndrome after retrobulbar anesthesia

Ipsilateral hypotropia with restricted elevation is an increasingly recognized strabismic entity resulting from injury to the inferior rectus muscle after local retrobulbar anesthesia. Eight patients with this disorder are described. Computed tomography of the orbit in three patients demonstrated isolated segmental enlargement of the retrobulbar portion of the inferior rectus muscle; the findings of magnetic resonance imaging in one patient was most compatible with fibrosis. Four patients underwent strabismus surgery consisting of adjustable recession of the affected inferior rectus muscle; all recovered single binocular vision in the functional fields of gaze postoperatively. Surgical exploration of the ipsilateral inferior rectus muscle demonstrated normal anatomy in the peribulbar portion of the muscle.