Surgery of bilateral superior oblique palsy.

Following head trauma, because the patient has no overt vertical or horizontal tropia to account for the complaint of diplopia, the symptoms are dismissed, when in fact cyclodiplopia resulting from the excyclotropic feature of bilateral superior oblique palsy is the cause. A prospective study of nine patients with bilateral superior oblique muscle palsy caused by head trauma and managed by an identical surgical regimen are presented. All patients had symptomatic cyclodiplopia that increased in downgaze. Cover testing performed in various gaze positions and in left and right head tilt positions plus the double Maddox rod tests confirmed the diagnosis. The four expected findings are left hypertropia (LHT) in right gaze and right hypertropia (RHT) in left gaze, RHT on right head tilt and LHT in left tilt, V pattern, and excyclodeviation. All patients received symmetrical bilateral superior oblique tendon surgery, using a modified technique originally described by Harada and Ito, which consisted of advancing the anterior tendon half along the equator of the globe toward the superior border of the lateral rectus muscle. Elimination of the cyclodiplopia symptom was achieved in all cases by reducing the quantity of excyclotropia.