ABSTRACT
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.
