Vertical Transposition of the Horizontal Rectus Muscles Combined With the Modified Kestenbaum Procedure for Correcting Abnormal Head Posture Due to Infantile Nystagmus Syndrome

We report a case of an infantile nystagmus syndrome (INS) with abnormal head posture (AHP) of head tilt and face turn treated with the modified Kestenbaum procedure and vertical transposition of the horizontal rectus muscles. A 23-year-old male patient with a history of eye shaking since early infancy presented to our hospital for correction of AHP. He had right-beating jerk nystagmus in both eyes, 15° right head tilt, and 25° right face turn. Given that the patient's nystagmus worsens with left head tilt and left face turn, this reinforces the diagnosis of AHP due to INS. We performed vertical transposition of the horizontal rectus muscles combined with the modified Kestenbaum procedure, that is, right lateral rectus muscle (LR) resection 9 mm + 1 muscle width (MW) upshift, right medial rectus muscle (MR) recession 6 mm + 1 MW downshift, left MR resection 7 mm + 1 MW upshift, and left LR recession 8 mm + 1 MW downshift. Postoperatively, a correction of 12° in head tilt and 30° in face turn significantly improved the patient's AHP. The modified Kestenbaum procedure and vertical transposition of the horizontal rectus muscles effectively corrected the AHP of head tilt and face turn due to INS.