Asymmetric superior oblique split Z-tendon lengthening for face turn in bilateral asymmetric superior oblique overaction and exotropia

Introduction: The aim was to evaluate the effectiveness of the procedure of the superior oblique split Z-tendon lengthening to collapse A pattern and treat face turn in a cohort of patients with both incomitant intermittent exotropia and a vertical deviation associated with a bilateral asymmetric superior oblique overaction. Methods: We retrospectively reviewed the clinical records of patients with facial turn associated with intermittent exotropia and bilateral asymmetric superior oblique overaction, who underwent superior oblique muscle split tendon lengthening and concurrent horizontal surgery between 2009 and 2017. Results: A total of eight patients met the inclusion criteria. The preoperative average face turn was 26.8° (range, 20°–5°), and it significantly improved to 5.4° (range, 2°–8°) (p < 0.05). All the patients showed an improvement in the face turn with neutralization of the vertical deviation. The vertical deviation in the right gaze for the patient with a right turn and the left gaze in patients with left turn improved significantly (values of p < 0.05). Conclusion: The superior oblique split Z-tendon lengthening was an effective procedure to collapse the A pattern and the treatment of the face turn in a cohort of patients with both incomitant intermittent exotropia and a vertical deviation associated with a bilateral asymmetric superior oblique muscle overaction with less complications, and less varying results.