# Digital therapy using dichoptic visual perceptual learning to improve stereopsis in children with intermittent exotropia

## TL;DR

A VR-based visual therapy improved 3D vision in children with intermittent exotropia, especially those with poor initial vision.

## Contribution

VR-based dichoptic visual perceptual learning is proposed as a personalized digital therapy for pediatric intermittent exotropia.

## Key findings

- Stereoacuity improved significantly in all participants after 8 weeks of VR-based training.
- 44.4% of children transitioned to sensory fusion, with 62.5% in the subnormal stereoacuity subgroup achieving fusion.
- The odds of achieving sensory fusion increased significantly in participants undergoing the therapy.

## Abstract

Intermittent exotropia impairs binocular vision and stereopsis in children, and visual perceptual learning (VPL) with dichoptic stimulation offers a potential therapy. This prospective exploratory study aimed to evaluate the efficacy of an 8-week at-home dichoptic VPL program delivered through virtual reality (VR)-based digital therapy in improving stereopsis and binocular sensory function in children with intermittent exotropia.

Children aged 6–16 years diagnosed with intermittent exotropia (n = 18) completed training at least 10 min per day, five days per week, using VR content tailored to their deviation angle. Outcomes included near stereoacuity (Titmus Stereo Test) and distance binocular sensory status (Worth 4 Dot test), measured at baseline and 8 weeks.

Stereoacuity improved significantly across all participants [mean change: −0.21 log arcsec; 95% confidence interval (CI), −0.28 to −0.13; P < 0.001], with greater improvement in a subgroup with subnormal baseline stereoacuity (mean change: −0.31 log arcsec; 95% CI, −0.39 to −0.23; P < 0.001). The odds of achieving sensory fusion increased significantly [odds ratio (OR) = 5.50; 95% CI, 1.38–22.0; P = 0.016], and 44.4% of participants showed transition to fusion. In the subnormal subgroup, 62.5% achieved fusion (OR = 21.0; 95% CI, 1.72–258.0; P = 0.017).

These findings suggest VR-based dichoptic VPL as a promising and personalized digital therapy to enhance binocular vision in pediatric intermittent exotropia, particularly in cases with subnormal stereoacuity.