Boergen modification of Harada-ito surgery with and without vertical muscle surgery for acquired unilateral superior oblique muscle palsy.

Purpose: The purpose is to report the results of the Boergen modification of the Harada-Ito procedure with and without simultaneous vertical muscle surgery in patients with acquired unilateral superior oblique muscle palsy.

Patients and methods: Files of patients with acquired unilateral superior oblique muscle palsy who were treated with Boergen modification of the Harada-Ito procedure were studied retrospectively. For each patient, age at the time of surgery, the presence of diplopia, compensatory head posture, and ocular deviation before and after surgery were retrieved. Results were evaluated 6 months after surgery.

Results: A total of 12 patients with a mean age of 32 years at the time of surgery (range 15-45 years) were included. The underlying etiology was head trauma in eleven patients. The modified Harada-Ito procedure alone was done for three cases (Group 1), and a simultaneous combination of this procedure and vertical muscle surgery was performed in nine patients (Group 2). The average intorsional effect in the primary position was 9.2° (8° in Group 1 and 9.6° in Group 2). The average correction of hypertropia in the primary position was 8.2 prism diopters (PD) (1 PD in Group 1 and 10.6 PD in Group 2). Diplopia in the primary position and downgaze were resolved in eleven patients and ten patients, respectively. Four patients had a compensatory head tilt at their last follow-up.

Conclusions: Boergen modification of the Harada-Ito procedure, alone and combined with vertical muscle surgery, successfully corrected primary position diplopia in the majority of the patients.