All participants completed the study. The office control score at distance changed by −1.0 (95% confidence interval [CI] = −1.6 to −0.4; P = .005; Cohen's d effect size, 0.93). The distant Look And Cover, then Ten seconds Observation Scale for Exotropia score and distant Newcastle control score total score changed by −0.7 (95% CI, −1.2 to −0.2; P = .02; Cohen's d effect size, 0.55) and −1.9 (95% CI, −2.8 to −1.0; P < .001; Cohen's d effect size, 1.37), respectively. Although there was no significant change in the angle of distance exodeviation (−1.8 prism diopter [Δ] less exodeviation; 95% CI, −3.74 to 0.14Δ; P = .11), a significant change was observed in the near angle (−4.4Δ less exodeviation; 95% CI, −7.3 to −1.5Δ; P = .01; Cohen's d effect size, 0.79). There was no significant change in stereopsis or the Chinese Intermittent Exotropia Questionnaire score.
In this select group of children with intermittent exotropia, 12 weeks of office-based vergence/accommodative therapy with home reinforcement resulted in a statistically and clinically significant improvement in the distance control of exodeviation and the near exodeviation magnitude. These results suggest that there is a need for a randomized clinical trial designed to determine the effectiveness of vision therapy as a treatment modality for intermittent exotropia.