Office-based vergence and anti-suppression therapy for the treatment of small-to-moderate angle intermittent exotropia: A randomised clinical trial.

PURPOSE: To evaluate the short-term (1 week after completion of treatment) effect of office-based vergence and anti-suppression therapy (OBVAT) on the Office Control Score when compared to observation alone in children with small-to-moderate angle intermittent exotropia (IXT). METHODS: In this single-masked (examiner masked), two-arm, single-centre randomised clinical trial, 40 participants, 6 to <18 years of age with untreated IXT, were randomly assigned to OBVAT or observation alone. Participants assigned to therapy received 60 min of OBVAT with home reinforcement once per week for 16 weeks. Therapy included vergence, accommodation and anti-suppression techniques. The primary outcome measure was the comparison of the distance Office Control Score between the two groups at the primary outcome visit (i.e., 17-week follow-up visit). RESULTS: At the primary outcome visit, the OBVAT group (n = 20) had a significantly better distance Office Control Score (adjusted mean difference: -0.9; 95% CI: -0.2 to -1.5; p = 0.008; partial eta squared: 0.19) than the observation group (n = 16). Participants from the OBVAT group were more likely than those from the observation group to have ≥1 point of improvement at the 17-week visit (OBVAT group: 75%; Observation group: 25%; p = 0.006). CONCLUSIONS: In this randomised clinical trial of participants aged 6 to <18 years with IXT, we found that the OBVAT group had a significantly better distance Office Control Score than the observation group at the 17-week visit. This study provides the first data from a randomised clinical trial demonstrating the effectiveness of OBVAT for improving the control of IXT. Eye care practitioners should consider OBVAT as a viable, non-surgical treatment option for IXT. A full-scale randomised clinical trial investigating the long-term effectiveness of OBVAT in treating IXT is warranted.

Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 2: non-surgical and surgical treatment options.

INTRODUCTION: Currently, there is no consensus regarding the management of intermittent exotropia (IXT), which includes both surgical and non-surgical treatment options. Nonsurgical management of IXT has been suggested and includes watchful observation, patching, overminus lenses, prism, and vision therapy/orthoptics. While a significant portion of IXT patients are treated by surgery, it is reported that there is a substantial tendency for reoperation or recurrence of IXT. This paper provides a comprehensive review of non-surgical and surgical treatment options for the IXT. METHODS: Search strategies involving combination of keywords including intermittent exotropia, divergence excess, basic exotropia, refractive error, glasses, spectacles, natural history, untreated, observe, occlusion, patch, overminus, overcorrecting minus, prism, vision therapy, orthoptic, anti-suppression, fusion exercise, and surgery were used in Medline. All English articles from 01/01/1900 to 01/09/2020 were reviewed. The reference list of the identified articles was also checked for additional relevant articles. Studies focused on animal models or strabismus associated with neurologic disorders or injury were excluded. The following filters were used for surgical management due to the abundance of reports: full text, randomized controlled trial, review, in the last 5 years. RESULTS: Appropriate optical correction of refractive error is generally the starting point for all management approaches, but there is a lack of randomized clinical trial data regarding this treatment modality. Randomized clinical trial data indicate that both observation and occlusion are reasonable management options for children 3-10 years old, and there were insufficient data to recommend occlusion for children 12-35 months old. While overminus lenses were found to improve the control of IXT when assessed wearing overminus spectacles, this improvement did not persist after the treatment ended. The result of the only randomized clinical trial on the effectiveness of base-in prism indicated that this treatment is no more effective than nonprism spectacles for improving control. A recent randomized clinical trial showed that vision therapy/orthoptics is effective in improving the control of IXT when compared to observation alone. Surgery was found to alter a number of clinical characteristics of IXT, including reducing the distance and near angle of deviation, reducing photophobia, improving health-related quality of life, stereopsis, and the Newcastle Control Score. However, there are no randomized clinical trial data comparing surgery with a control group such as placebo or a no treatment observation group. DISCUSSION: Rigorously designed clinical trials to investigate the effectiveness of non-surgical and surgical treatments for intermittent exotropia are needed.

Vision therapy for intermittent exotropia: A case series

Introduction: We evaluated the effectiveness of office-based vergence/accommodative therapy with home reinforcement for intermittent exotropia in a private practice environment. Methods: This was a retrospective chart review study. Patients who received office-based vision therapy for intermittent exotropia in a private optometric clinic were reviewed. Patients with intermittent exotropia treated with and without strabismus surgery were both included. The pre-therapy baseline data were compared to the re-evaluation data obtained at the last therapy session. All patients received office-based vergence/accommodative therapy administered by a trained therapist during a 60 min office visit every one to two weeks, combined with home reinforcement for a minimum of 15 min, five times per week. The primary outcome measure in this study was the change in the Office Control Score from the pre-therapy visit to the post-therapy visit. The hypothesis was that office-based vergence/accommodative therapy would significantly improve the Office Control Score. Results: Forty patients aged from 5 to 22 years old fulfilled the inclusion criteria. Eight of them were postoperative patients. After treatment, there was a change of −1.1 ± 1.6 (p < 0.001, z = 3.73, effect size: 0.42) and −1.1 ± 1.4 (p < 0.001, z = 4.26, effect size: 0.48) in distance and near Office Control Score, respectively. In the subgroup analysis, significant improvements in the Office Control Score were observed in both the operated and unoperated intermittent exotropes at distance and near. Conclusion: This study showed that office-based vergence/accommodative therapy with home reinforcement significantly improved the distance and near control of exodeviation in both operated and unoperated intermittent exotropia patients in a private practice environment. (AU)