Botulinum toxin injection for treatment of acute traumatic superior oblique muscle palsy

Purpose: to evaluate the outcomes of botulinum toxin injection into the inferior oblique (io) muscle for management of unilateral acute traumatic superior oblique (so) palsy. methods: in this prospective case series,10-20 units of botulinum toxin a (dysport,ipsen,biopharm ltd.,wrexham,uk) was injected into the ipsilateral io muscle of 13 consecutive patients with unilateral acute traumatic so palsy. all patients received injections within four weeks of the incident. results: mean age was 29 ± 15 years and 12 (92%) subjects were male. mean amount of hypertropia (in primary position) was decreased from 10.0 ± 3.9δ at baseline to 4.6 ± 8.9δ,one month after the injection,and to 1.5 ± 2.7δ at final follow-up (p = 0.001). io overaction improved from 2.7 ± 0.6 to 1.0 ± 1.2 and 0.6 ± 0.9 (p ≤ 0.001),and subjective torsion from 5.3 ± 3.9 to 3.2 ± 3.4 and 1.6 ± 2.5 degrees (p ≤ 0.001),at the same time intervals respectively. one month after the injection as well as at final follow-up,10 (77%) patients were diplopia-free in primary and reading positions. subgroup analysis showed that patients who recovered had less baseline hypertropia as compared to those who failed (8.3δ vs. 15.7δ,respectively; p = 0.01). all patients with a favorable outcome had baseline hypertropia of 10δ or less. conclusion: a single injection of bta into the io muscle can rapidly and safely resolve symptomatic diplopia in patients with acute traumatic so palsy,while waiting for spontaneous recovery. © 2015 journal of ophthalmic and vision research | published by wolters kluwer - medknow.