Analysis of anomalous head posturing in patients with infantile nystagmus syndrome

Correction of horizontal and torsional compensatory head posture in infantile nystagmus syndrome using horizontal rectus muscle recession and resection with vertical transposition

Infantile nystagmus syndrome (INS) is often characterized by an identifiable null zone. When the null zone is not in the straight-ahead gaze, a compensatory head posture (CHP) is adopted by the patient to achieve best possible vision. Various surgical procedures have been recommended to correct a CHP which is clinically predominant in one dimension of yaw (lateral rotation), pitch (anterior or posterior flexion/extension) or roll (lateral flexion). However, the presence of a complex CHP which is clinically evident in more than one dimension, warrants either a combination of multiple techniques or a stepwise approach. We report the case of a 26-year-old male with INS with an eccentric null and a multi-dimensional complex CHP of 30º left face turn, 20º right head tilt and 10º chin depression. The patient was managed by all four horizontal rectus muscle recession and resection with full tendon vertical transposition to address the face turn and head tilt. He underwent lateral rectus muscle (LR) recession with upward transposition and medial rectus muscle (MR) resection with downward transposition in the right eye. MR recession with upward transposition and LR resection with downward transposition were performed in the left eye. Postoperatively. the head posture improved significantly for both distance and near viewing. The chin depression also reduced after the procedure. He developed transient diplopia due to a small vertical deviation after the surgery, which was managed by prisms and fusional exercises. Thus, horizontal rectus muscle recession and resection combined with vertical transposition may be helpful to simultaneously improve the head tilt associated with the face turn, obviating the need for vertical rectus muscle or oblique muscle surgery.