Surgical Management of Complex Anomalous Head Posture in Idiopathic Infantile Nystagmus

Abstract

Idiopathic infantile nystagmus (IIN) is usually associated with a null zone, which is the zone of minimal nystagmus intensity. An anomalous head posture (AHP) is adopted to shift the null zone from an eccentric position to primary position. A complex AHP may include head position involvement in different ocular axes-namely face turn, chin elevation or depression and head tilt or a combination of these. Surgically, various procedures have been described for correction of this condition. We evaluated 2 children aged six and ten years, who presented with shaking of eyes along with presence of a complex AHP. First child had 20 degrees right face turn, 20 degrees right head tilt and 10 degrees of chin elevation. She underwent a combination of 2 procedures-augmented Anderson’s procedure for correction of right face turn and modification of Kestenbaum procedure for right head tilt along with bilateral IR recession, for correction of chin elevation. Postoperatively, AHP was satisfactorily corrected to 5 degrees face turn and minimal head tilt, and it remained stable for one year. The second child had left face turn 15 degrees, with right head tilt of 20 degrees and chin depression 10 degrees. He underwent a combination of 2 procedures-augmented Anderson’s procedure for correction of left face turn and modification of Kestenbaum procedure for right head tilt along with bilateral SR recession, for correction of chin depression. Postoperatively, AHP was satisfactorily corrected to 5 degrees face turn and minimal head tilt, which remained stable over a period of one year. In both cases, AHP was corrected by operating on only 2 muscles in each eye (one horizontal and one vertical) at a time. As both cases presented with combination of both torsional and vertical components of AHP, we decided to treat them both by surgery on a single vertical rectus muscle bilaterally to correct the chin position (elevation or depression), as well as torticollis (transposition of vertical recti, either nasally or temporally as needed). Since a third rectus muscle was not operated upon, there was a lesser possibility of developing anterior segment ischaemia. Additionally, as all components of AHP were corrected in one session, need for a second procedure under general anaesthesia to correct residual AHP was avoided in both cases.