Secondary or new compensatory head posture after Anderson-Kestenbaum surgery

Kestenbaum procedure with combined muscle resection and tucking for nystagmus-related head turn

BACKGROUND

Literature has dealt extensively with dose-effect relations for recess-resect procedures for correction of horizontal nystagmus-related head turn. However, muscle tucking procedures have some advantages compared to resection procedures. Aim of this study was to evaluate dose-effect relations of Kestenbaum surgery with symmetrical combined recession and tucking (instead of resection) of the horizontal rectus muscles for the reduction of a nystagmus-related head turn.

METHODS

In a retrospective study, clinical findings of 42 patients who consecutively underwent treatment in our institution between 2000 and 2011 were investigated. The patients were aged 4-57 years (median age 6 years). For all patients, surgery aimed to correct a horizontal head turn (to the right: 18 patients) due to infantile nystagmus. The head turn was measured with a goniometer with the patient fixing the smallest age-appropriate target distinguishable for the patient.

RESULTS

The median absolute head turn before surgery was 30° (min. 15°, max. 45°). The four horizontal rectus muscles were recessed or tucked between 5.5 and 10 mm, median 9 mm. All four muscles were recessed or tucked for the same amount. At the first postoperative day, the median dose-effect relation was 1.88° reduction of head turn per millimeter surgery on one eye (min. 0.5°/mm, max. 3.2°/mm). The median head turn was 0° (min. -20°, max. 15°). Surgery was considered successful in 88% of the patients with a reduction of the head turn to max. 10°. Data of 36 patients were available for the long-term postoperative period (median 1.5 years; min. 6 weeks, max. 11 years). The median head turn was 10° (min. -16°, max. 30°). The median dose-effect relation was reduced to 1.35°/mm per eye (min. 0°/mm, max. 2.9°/mm). Surgery was considered successful in 72 % of the patients with a reduction of the head turn to max. 10°. Three patients showed an overcorrection with a head turn of 8°, 15° and 16° to the other side. A squint has not been induced.

CONCLUSIONS

The dose-effect relation for Kestenbaum surgery with symmetrical combined recession and tucking of the horizontal rectus muscles is comparable to the dose-effect relation reported by other authors for symmetrical combined recession and resection.

Abnormal head position in infantile nystagmus syndrome

Infantile nystagmus is an involuntary, bilateral, conjugate, and rhythmic oscillation of the eyes which is present at birth or develops within the first 6 months of life. It may be pendular or jerk-like and, its intensity usually increases in lateral gaze, decreasing with convergence. Up to 64% of all patients with nystagmus also present strabismus, and even more patients have an abnormal head position. The abnormal head positions are more often horizontal, but they may also be vertical or take the form of a tilt, even though the nystagmus itself is horizontal. The aim of this article is to review available information about the origin and treatment of the abnormal head position associated to nystagmus, and to describe our treatment strategies.