Long-term follow-up after vertical extraocular muscle surgery to correct abnormal vertical head posture

Purpose: To report outcomes of vertical extraocular muscle surgery to correct abnormal vertical head posture in children with horizontal infantile nystagmus.

Methods: Retrospective case series of seven patients evaluated at one institution with abnormal vertical head position (chin-up or chin-down) in the setting of horizontal infantile nystagmus. All patients underwent bilateral vertical extraocular muscle surgery with the same surgeon. Pre- and postoperative vertical head position under binocular viewing conditions was the primary outcome measure. Secondary outcomes included visual acuity, stereopsis, degree of cyclotorsion, and residual ocular alignment.

Results: Seven children with infantile nystagmus syndrome, ranging in age from 4 months to 5 years at presentation, underwent extraocular muscle surgery to correct chin-down or chin-up head position associated with a null position in the setting of horizontal nystagmus. Five children had other ocular pathology (albinism, n = 4; cone-rod dystrophy, n = 1). Five of the seven patients had combined vertical recti and oblique muscle surgery. Three of the patients had additional extraocular muscle surgery to correct horizontal misalignment (exotropia, n = 2; esotropia, n = 1). One patient underwent a separate Kestenbaum procedure (bilateral horizontal resection/recession) to correct concomitant horizontal face turn. Median postoperative follow-up was 8.0 years (range 1-9.5 years). Postoperatively, three patients had complete resolution of their abnormal head position, and three had an improvement in their head posture, with a mean reduction in original vertical head position of 25 degrees. One of these patient had a reversal of their head position from a chin-up to a small chin-down position. Only one patient had no clinically significant improvement in their head position. No patients had signs or symptoms of cyclotorsion postoperatively.

Conclusion: Combined vertical recti and oblique muscle surgery can successfully improve and even resolve vertical head posture, and prevents cyclorotary disorders postoperatively.