Superior oblique tucking with versus without additional inferior oblique recession for acquired trochlear nerve palsy

Inferior oblique recession (IOR), superior oblique tucking or advancement (SOT) and a combination of both (SOT&IOR) are most popular as treatments for acquired trochlear nerve (N.IV) palsy. Recently, it has been reported that results of a modified SOT technique and SOT&IOR were nearly equivalent. We investigated the effects of SOT and SOT&IOR in 37 patients with unilateral acquired isolated N.IV palsy.

Retrospective study of patients with unilateral acquired N.IV palsy who were operated at the University Hospitals of Giessen (1996 to 2007) and Essen (2003 to 2007). Examinations with Harms' tangent scale (2.5 m, dark red glass in front of non-paretic eye) were performed before and 3 months after pure SOT or SOT + IOR. When the palsy was on OS, squint angles were transformed corresponding to palsy on OD.

horizontal, vertical and cyclotorsional deviations in nine diagnostic gaze directions and the field of binocular fusion.

In total, it was possible to examine 37 patients 3 months post surgery: 16 had received pure SOT, and 21 SOT&IOR. Preoperative deviations did not differ significantly between the pure SOT and SOT&IOR groups. Dosage was 6 to 8 mm for pure SOT (median, 8) and 8 to 18 mm (median, 11) for SOT&IOR (with 4 to 8 mm SOT). At 3 months, elevation deficiency in adduction was less severe with pure SOT compared to SOT&IOR, but at the same time the effect on the vertical deviation was less pronounced.

Additional IOR augments the effect of SOT, but also its side-effects, i.e. consecutive Brown's syndrome.