Clinical Manifestations and Surgical Outcomes of Intermittent Exotropia with or without Dissociated Vertical Deviation

ABSTRACT

PURPOSE: Clinical manifestations and surgical outcomes of intermittent exotropia with or without dissociated vertical deviation (DVD) were evaluated. METHODS: Patients who were diagnosed with intermittent exotropia following surgical correction were divided into 2 groups 66 patients with DVD (DVD group) and 81 patients without DVD (XT group). The postoperative deviation between exodeviation of 10 prism diopters (PD) and esotropia of 5 PD was considered surgically successful. RESULTS: The onset of strabismus occurred at an earlier age in the DVD group. There were more cases of nystagmus, inferior oblique muscle overaction, superior oblique muscle overaction, and AV pattern in the DVD group than in the XT group, but there were no differences between the 2 groups in terms of head tilt, amblyopia, and age at first operation. While exodeviation in the DVD group was smaller than in the XT group, stereopsis in the DVD group was statistically worse than in the XT group in the Titmus test. At postoperative 1 month, the XT group had better surgical outcome, but at postoperative 6 and 12 months, there were no differences in the surgical outcomes of intermittent exotropia between the 2 groups. Regarding DVD surgery, a postoperative DVD angle less than 10 PD accounted for 90.0% of the cases. CONCLUSIONS: Intermittent exotropia combined with DVD had worse stereoacuity and lesser exodeviation. There was no statistically significant difference in the surgical outcomes of intermittent exotropia with or without DVD.