Study protocol for a randomized controlled trial of the NEIVATECH virtual reality system to improve visual function in children with anisometropic amblyopia

Pilot Study Assessing the Safety and Acceptance of a Novel Virtual Reality System to Improve Visual Function

PURPOSE

To assess the feasibility of the clinical use of a novel Virtual Reality (VR) training software designed to be used for active vision therapy in amblyopic patients by determining its preliminary safety and acceptance on the visual function of healthy adults.

METHODS

Pilot study enrolling 10 individuals (3 men, 7 women, mean age: 31.8 ± 6.5 years) with a best-corrected visual acuity (BCVA) of ≥ .90 (decimal) in both eyes were evaluated before and after 20 minutes of exposure to the NEIVATECH VR system using the HTC Vive Pro Eye head mounted display. Visual function assessment included near (40 cm) and distance (6 m) cover test (CT), stereopsis, binocular accommodative facility (BAF), near point of convergence (NPC), near point of accommodation (NPA), accommodative-convergence over accommodation (AC/A) ratio and positive and negative fusional vergences. Safety was assessed using the VR Sickness Questionnaire (VRSQ) and acceptance using the Technology Acceptance Model ;(TAM). Changes in all these variables after VR exposure were analyzed.

RESULTS

Short-term exposure to the NEIVATECH VR system only induced statistically significant changes in distance phoria (p = .016), but these changes were not clinically relevant. No significant changes were observed in VRSQ oculo-motricity and disorientation scores after exposure (p = .197 and .317, respectively). TAM scores showed a good acceptance of the system in terms of perceived enjoyment and perceived ease of use, although some concerns were raised in relation to the intention-to-use domain.

CONCLUSION

Exposure to the NEIVATECH VR system does not seem to adversely affect the visual function in healthy adults and its safety and acceptance profile seems to be adequate for supporting its potential use in other populations, such as amblyopic patients.

Current Developments in the Management of Amblyopia with the Use of Perceptual Learning Techniques

Background and Objectives: Amblyopia is a neurodevelopmental disorder caused by interocular suppression of visual input, affecting visual acuity, stereopsis, contrast sensitivity, and other visual functions. Conventional treatment comprises occlusion of the sound eye. In recent years, novel therapies that deploy perceptual learning (PL) principles have been introduced. The purpose of this study is to assess the latest scientific data on this topic. Materials and Methods: For this purpose, we conducted a literature search for relevant studies published during the previous 4 years (2020-2023). Results: A plethora of visual perceptual learning protocols have been recently developed. Dichoptic video games, contrast rebalanced movies, and online perceptual training platforms are the main formats. Perceptual learning activates neuroplasticity, overcomes interocular suppression, and improves the visual impairments induced by amblyopia. Conclusions: This novel treatment is effective in both children and adults, as well as in patients non-responding to patching.

Effects of virtual reality on the treatment of amblyopia in children: A systematic review and meta-analysis

PROBLEM

Virtual reality technology has been used to treat amblyopia in children. However, it is unclear how virtual reality technology differs from conventional patching therapy in terms of effectiveness.

ELIGIBILITY CRITERIA

Eligible randomized controlled studies were retrieved from PubMed, Embase, Scopus, the Cochrane Library, and Web of Science through February 2023.

SAMPLE

Eight studies included 10 trials with 459 participants were included in the current meta-analysis. Two studies (Herbison et al., 2016; Huang et al., 2022) included two trials each. Thus, a total of ten trials were included in the current meta-analysis.

RESULTS

Overall, virtual reality technology treatment significantly improved visual acuity by 0.07 log MAR (95% confidence interval [CI], -0.11 to -0.02; P < 0.001; I2 = 94.4%) compared with traditional patching therapy. In addition, subgroup analyses also revealed that treatment with virtual reality technology was more effective when the child was younger than seven years old, or when the duration of the intervention was no more than twenty hours.

CONCLUSIONS

Virtual reality technology treatment showed significant effects in improving visual acuity in children who were seven years of age or younger with amblyopia.

IMPLICATIONS

Virtual reality technology treatment is effective in treating amblyopia in children. Virtual reality therapy is also entertaining and popular among children and can be applied to the treatment of amblyopia in children in the future.

Amblyopia Treatment through Immersive Virtual Reality: A Preliminary Experience in Anisometropic Children

The use of digital devices provides a wide range of possibilities for measuring and improving visual function, including concepts such as perceptual learning and dichoptic therapy. Different technologies can be used to apply these concepts, including, in recent years, the introduction of virtual reality (VR) systems. A preliminary experience in treating anisometropic amblyopia through an immersive VR device and using prototype software is described. A total of 4 children were treated by performing 18 office-based sessions. Results showed that distance VA in amblyopic eyes remained constant in two subjects, whereas the younger subjects improved after the training. Near VA improved in three subjects. All subjects showed an increase in the stereopsis of at least one step, with three subjects showing a final stereopsis of a 60 s arc. A total of three subjects showed an increase of approximately 0.5 CS units for the spatial frequency of 3 cpd after the training. Results from this pilot study suggest that visual training based on perceptual learning through an immersive VR environment could be a viable treatment for improving CS, VA, and stereopsis in some children with anisometropic amblyopia. Future studies should support these preliminary results.