Abstract
Purpose :
To determine whether home-based vergence exercises improve compensatory visual function in children and adolescents with intermittent exotropia (IXT).
Methods :
Retrospective chart review was conducted for patients with IXT seen by the last author (AR) between 2010 to 2021. Patients with ≥ 2 visits and no history of amblyopia or other ocular pathology were included in two groups: 1) Participated in home-based computer and free-space exercises (Treated), 2) Did not participate in any home-based exercises (Observed). We abstracted eye alignment at distance and near, type of IXT, near point of convergence (NPC), and convergence amplitude (CA) at baseline and follow-up visits. NPC outcomes were a “success” if NPC was < 7 cm at follow-up and/or decreased ≥ 4 cm between visits. CA outcomes were a “success” if CA passed Sheard’s criterion and convergence ranges > 15Δ at follow-up and/or increased ≥ 10Δ between visits. Wilcoxon tests were used to compare within and between group differences at α = 0.05. “Success” outcomes were compared using Fisher’s exact test.
Results :
The Treated group (N = 25; 15 females; age 9.3 ± 4.4 years) had a mean duration between visits of 2.4 ± 1.8 years. 71% met NPC “success” criteria and 70% met CA “success” criteria. NPC break (mean difference (MD): -4.7 cm, 95% confidence interval (CI): -7.5 to -1.9, p < 0.01), NPC recovery (MD: -5.1 cm, 95% CI: -8.1 to -2.0, p < 0.01), CA break (MD: 14 Δ, 95% CI: 8.0 to 20, p < 0.001), and CA recovery (MD: 12 Δ, 95% CI: 7.5 to 17.0, p < 0.01) were significantly different between baseline and follow up visits. The Observed group (N = 21; 12 females; age 10 ± 3.0 years) had a mean duration between visits of 1.8 ± 1.3 years. 19% met NPC “success” criteria and 9.5% met CA “success” criteria, but only 5 patients had CA recorded limiting further analysis. There was no within group difference between visits for NPC break or recovery. The Treated group had greater improvement in NPC break (p < 0.01) and recovery (p = 0.02), and a higher rate of meeting NPC “success” criteria than the Observed group (p < 0.001).
Conclusions :
Home-based vergence exercises improved NPC and CA measures in children and adolescents with IXT. These results compel the need for prospective study validation to determine if improving compensatory vergence mechanisms can enhance IXT control, reduce the impact of social stigma, delay the need for surgery, or improve poor surgical outcomes.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.