Impact of Online Video Game-Based Dichoptic Training on Binocular Vision Rehabilitation in Post-surgical Patients with Intermittent Exotropia.

INTRODUCTION: Dichoptic training has emerged as a promising rehabilitation approach for improving binocular visual function in patients with strabismus. A prospective observational study design was employed to assess the effectiveness of online video game-based dichoptic training in rehabilitating binocular visual function in patients who had undergone an operation for intermittent exotropia. METHODS: A total of 64 patients who had undergone an operation for intermittent exotropia were recruited and divided into the training group and the control group based on whether they would receive the dichoptic training. The dichoptic training was conducted for 3 months in the training group and the control group would not accept any form of orthoptic therapy. Assessments of binocular visual functions and deviation were conducted at baseline, 3-month and 6-month follow-up. RESULTS: Twenty-nine participants in the training group (mean 9.69 ± 2.66 years old) and 26 participants in the control group (mean 8.41 ± 2.64 years old) completed follow-up. At both 3- and 6-month follow-ups, the training group showed superior distance stereopsis compared to the control group, with near stereopsis only showing significant difference at the 6-month follow-up. Additionally, the training group exhibited significantly less distance exo-deviation drift than the control group at these times, and no significant difference was observed in near exo-deviation drift between the groups. The control group had a significantly higher rate of suboptimal surgical outcomes at both the 3- and 6-month follow-up. However, no significant differences were observed in simultaneous perception and fusion functions between the two groups. CONCLUSIONS: Online video game-based dichoptic training has the potential to become a novel postoperative rehabilitation strategy for patients with intermittent exotropia.

Exploring Binocular Visual Attention by Presenting Rapid Dichoptic and Dioptic Series.

This study addresses an issue in attentional distribution in a binocular visual system using RSVP tasks under Attentional Blink (AB) experimental protocols. In Experiment 1, we employed dichoptic RSVP to verify whether, under interocular competition, attention may be captured by a monocular channel. Experiment 2 was a control experiment, where a monoptic RSVP assessed by both or only one eye determines whether Experiment 1 monocular condition results were due to an allocation of attention to one eye. Experiment 3 was also a control experiment designed to determine whether Experiment 1 results were due to the effect of interocular competition or to a diminished visual contrast. Results from Experiment 1 revealed that dichoptic presentations caused a delay in the type stage of the Wyble's eSTST model, postponing the subsequent tokenization process. The delay in monocular conditions may be further explained by a visual attenuation, due to fusion of target and an empty frame. Experiment 2 evidenced the attentional allocation to monocular channels when forced by eye occlusion. Experiment 3 disclosed that monocular performance in Experiment 1 differs significantly from conditions with interocular competition. While both experiments revealed similar performance in monocular conditions, rivalry conditions exhibit lower detection rates, suggesting that competing stimuli was not responsible for Experiment 1 results. These findings highlight the differences between dichoptic and monoptic presentations of stimuli, particularly on the AB effect, which appears attenuated or absent in dichoptic settings. Furthermore, results suggest that monoptic presentation and binocular fusion stages were a necessary condition for the attentional allocation.

Rehabilitation of amblyopia using a digital platform for visual training combined with patching in children: a prospective study.

PURPOSE: To assess the possible benefits of the use of perceptual learning and dichoptic therapy combined with patching in children with amblyopia over the use of only patching. METHODS: Quasi-experimental multicentric study including 52 amblyopic children. Patients who improved their visual acuity (VA) by combining spectacles and patching were included in patching group (PG: 20 subjects), whereas those that did not improved with patching performed visual training (perceptual learning + dichoptic therapy) combined with patching, being assigned to the visual treatment group (VT: 32 subjects). Changes in VA, contrast sensitivity (CS), and stereopsis were monitored during a 6-month follow-up in each group. RESULTS: Significant improvements in VA were found in both groups at 1 month (p < 0.01). The total improvement of VA was 0.18 ± 0.16 and 0.31 ± 0.35 logMAR in PG and VT groups, respectively (p = 0.317). The Wilcoxon effect size was slightly higher in VT (0.48 vs. 0.54) at 6 months. An enhancement in CS was observed in the amblyopic eye of the VT group for all spatial frequencies at 1 month (p < 0.001). Likewise, the binocular function score also increased significantly in VT group (p = 0.002). A prediction equation of VA improvement at 1 month in VT group was obtained by multiple linear regression analysis (p < 0.001, R2 = 0.747). CONCLUSIONS: A combined treatment of visual training and patching is effective for obtaining a predictable improvement of VA, CS, and binocularity in patching-resistant amblyopic children.

Efficacy of Amblyopia Treatments in Children Up to Seven Years Old: A Systematic Review.

Amblyopia is a neurodevelopmental disorder of the visual system that impairs the vision of millions of children worldwide. Amblyopia is best treated within the sensitive period of visual development when a child is up to seven years of age. Currently, the gold standard for early treatment of childhood amblyopia is patching, with new treatments emerging in recent years. We aim to evaluate the effectiveness of these newly developed treatments for amblyopia in children aged seven years and younger while comparing them to the current industry standard of patching. We searched online databases including PubMed, Google Scholar, and Cochrane Library for randomized controlled trials (RCTs), systematic reviews, meta-analyses, and narrative reviews relating to amblyopia treatment in children aged seven and younger. We only included articles and studies completed within the last five years and those written in the English language. After compiling a list of 297 articles, we removed duplicates, articles without an available full text, and those not relevant to our topic. Of the remaining 51 articles, we were left with 22 after reading abstracts and removing further irrelevant articles. We did a quality assessment on the remaining 22 articles and were left with 14 articles for our systematic review after removing eight low-quality articles. Of the 14 articles, we had eight RCTs, two systematic reviews, one comparative interventional study, and three narrative reviews. Seven of the articles contained data reinforcing the effectiveness of patching while comparing it to other treatment modalities. Three of the articles had data supporting spectacle correction, including a novel form called alternative flicker glass which delivers occlusion therapy via a spectacle frame with unique lenses, and ultimately deemed it at least as effective or more than patching. Data from three articles supported the use of surgery to successfully correct the angle of strabismus. Findings from five articles backed the use of pharmacologic therapy, specifically atropine when used alongside patching as a more effective alternative to patching solely. However, levodopa plus patching had no advantage over patching alone. Additionally, seven articles addressed the use of virtual reality (VR) and dichoptic therapy as prospective treatments for childhood amblyopia. VR therapy proved beneficial when used within one week after strabismus surgery. Dichoptic training was also effective in improving amblyopic-eye visual acuity when used on its own or in conjunction with spectacles. Furthermore, dichoptic movie therapy was found to be more effective than patching. Thus, we found multiple highly effective treatments for childhood amblyopia that are as effective or more than patching. Future studies should consider prescribing these treatments to larger cohorts while also performing a cost-benefit analysis for each treatment. In addition, more needs to be learned about the potential adverse side effects of these treatments, especially for pharmaceutical therapy.

A comparative study of stereopsis measurements: analyzing natural conditions versus dichoptic presentation using smartphones and ultraviolet printer technology.

Background: Accurate differentiation between stereopsis assessments in the natural and dichoptic presentation states has proven challenging with commercial stereopsis measurement tools. This study proposes a novel method to delineate these differences more precisely. Methods: We instituted two stereopsis test systems predicated on a pair of 4K smartphones and a modified Frisby Near Stereotest (FNS) version. Stereoacuity was evaluated both in the natural environment state (via the modified FNS) and the dichoptic state (via smartphones). Thirty subjects aged 20 to 28 years participated in the study with the best-corrected visual acuity (VA) of each eye no less than 0 logMAR and stereoauity of no worse than 40″. Varying degrees of monocular VA loss were induced using the fogging method, while this study does not explore conditions where the VA of both eyes is worse than 0 logMAR. Results: When the VA difference between the two eyes did not exceed 0.2 logMAR, the modified FNS produced lower stereoacuity values compared to the 4K smartphones (Wilcoxon signed-rank test: difference = 0 logMAR, Z = -3.879, P < 0.001; difference = 0.1 logMAR, Z = -3.478, P = 0.001; difference = 0.2 logMAR, Z = -3.977, P < 0.001). Conversely, no significant differences were observed when the binocular vision difference exceeded 0.2 logMAR (difference = 0.3 logMAR, Z = -1.880, P = 0.060; difference = 0.4 logMAR, Z = -1.784, P = 0.074; difference = 0.5 logMAR, Z = -1.812, P = 0.070). Conclusion: The findings suggest that stereoacuity values measurements taken in the natural environment state surpass those derived from the dichoptic presentation. However, the observed difference diminishes as stereopsis decreases, corresponding to an increase in induced anisometropia.

Supervised dichoptic gaming versus monitored occlusion therapy for childhood amblyopia: Effectiveness and efficiency.

PURPOSE: To compare the effectiveness and efficiency of supervised dichoptic action-videogame play to occlusion therapy in children with amblyopia. METHODS: Newly diagnosed children with amblyopia aged 4-12 years were recruited, excluding strabismus >30PD. After 16 weeks of refractive adaptation children were randomized to gaming 1 h/week supervised by the researcher, or electronically monitored occlusion 2 h/day. The gaming group played a dichoptic action-videogame using virtual reality goggles, which included the task of catching a snowflake presented intermittently to the amblyopic eye. Contrast for the fellow eye was self-adjusted until 2 identical images were perceived. The primary outcome was visual acuity (VA) change from baseline to 24 weeks. RESULTS: We recruited 96 children, 29 declined and 2 were excluded for language or legal issues. After refractive adaptation, 24 of the remaining 65 no longer met the inclusion criteria for amblyopia, and 8 dropped out. Of 16 children treated with gaming, 7 (6.7 years) completed treatment, whereas 9 younger children (5.3 years) did not. Of 17 treated with occlusion, 14 (5.1 years) completed treatment and 3 (4.5 years) did not. Of 5 children with small-angle strabismus, 3 treated with occlusion completed treatment and 2 treated with gaming did not. Median VA improved by 0.30 logMAR (IQR 0.20-0.40) after gaming, 0.20 logMAR (0.00-0.30) after occlusion (p = 0.823). Treatment efficiency was 1.25 logMAR/100 h (range 0.42-2.08) with gaming, 0.08 (-0.19-0.68) with occlusion (p < 0.001). CONCLUSION: Dichoptic gaming seems a viable alternative for older children with refractive amblyopia after glasses adaptation. Treatment efficiency with gaming under continuous supervision was 15 times higher than with occlusion at home.

Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy.

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia.Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test.Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06-0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group.Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

Treatment of Anisometropic Amblyopia with a Dichoptic Digital Platform in Argentinian Children and Adults.

PURPOSE: To evaluate and compare the results of dichoptic training in Argentinian children and adults with anisometropic amblyopia. METHODS: Prospective non-comparative study enrolling 41 subjects with anisometropic amblyopia (age, 6-60 years old). Two groups were differentiated according to age, children (6-16 years, 24 subjects) and adults (>17 years, 17 subjects). All patients were treated with the Bynocs® platform (Kanohi Eye Pvt. Ltd, India) following a protocol of 30 sessions of training of 30 min daily 5 times a week for 6 weeks. Changes in corrected distance visual acuity (CDVA) and binocular function (BF) score with treatment were analyzed. RESULTS: In the whole sample, CDVA in the amblyopic eye improved significantly, with a mean change of 0.30 logMAR (p < .001). Likewise, a significant improvement was also found in BF score (p < .001), with a mean change of 1.14 log units. The change achieved in CDVA was significantly correlated with the baseline CDVA in the amblyopic eye (r=-0.568, p < .001). Furthermore, no significant differences were found between age groups in the change achieved in CDVA (p = .431) and BF with therapy (p = .760). CONCLUSIONS: Dichoptic training with the digital platform evaluated provides an effective improvement of visual acuity and binocular function in children and adults with anisometropic amblyopia.

Monocular and binocular mechanisms detect modulations of dot density and dot contrast.

Strong reciprocity has been demonstrated between (1) spatial modulations of dot density and modulations of dot luminance, and (2) modulations of dot density and modulations of dot contrast, in textures. The latter are much easier to detect when presented in phase with one another than when presented 180° out of phase, although out-of-phase modulations can also be detected given sufficient amplitude. This result supports the existence of two detection mechanisms: one that is excited by both density modulations and contrast modulations (quiescent when those modulations are presented 180° out of phase) and another that is relatively insensitive to either density modulations or contrast modulations (thus remaining stimulated regardless of phase angle). We investigate whether the mechanism responsible for detecting out-of-phase modulations depends on high-level computations (downstream from the confluence of monocular signals) or whether both mechanisms are situated at the monocular level of visual processing. Specifically, density-modulated and/or contrast-modulated stimuli were presented monocularly (i.e., to the same eye) or dichoptically (i.e., to opposite eyes). Out-of-phase modulations of density were much easier to detect when presented dichoptically. A dichoptic advantage was also found for out-of-phase density and contrast modulations. These dichoptic advantages imply conscious access to a mechanism at the monocular level of processing. When density modulations were presented dichoptically, 180° out of phase, detection thresholds were highest. Consequently, a mechanism with binocular input must also contribute to the detection of these modulations. We describe a minimal, image-based model for these results that contains one monocular computation and one binocular computation.

Dichoptic Game Training in Strabismic Amblyopia Improves the Visual Evoked Response.

Dichoptic video gaming offers an alternative approach in amblyopia treatment by allowing different information to be presented in the two eyes, resulting to reduced suppression and/or enhanced fusion. The aim of this case report series is to evaluate the outcome of supervised dichoptic training, with the use of video games in a virtual reality (VR) system, on far and near visual acuity (VA), stereoacuity, and the visual evoked response of an adult and two children with strabismic amblyopia. Results suggest that despite the absence of improvement in VA following supervised dichoptic training, a remarkable increase in stereoacuity was evident with a concurrent decrease in phorias. Moreover, an improvement in the P100 latency of the pattern visual evoked potentials (VEPs) in the amblyopic eye was observed in all participants. Finally, at least two sessions per week were completed for each patient under continuous supervision, implying sufficient compliance and treatment efficiency with dichoptic video gaming. Supervised dichoptic training, consisting of at least 20 hours of video gaming using a VR system, improves stereoacuity and the latency of the visual evoked response in the amblyopic eye. This probably occurs by overcoming its suppression, indicating that the speed of visual processing, as evaluated by pattern VEPs, may precede improvements in VA.

Sensory eye dominance plasticity in the human adult visual cortex.

Sensory eye dominance occurs when the visual cortex weighs one eye's data more heavily than those of the other. Encouragingly, mechanisms underlying sensory eye dominance in human adults retain a certain degree of plasticity. Notably, perceptual training using dichoptically presented motion signal-noise stimuli has been shown to elicit changes in sensory eye dominance both in visually impaired and normal observers. However, the neural mechanisms underlying these learning-driven improvements are not well understood. Here, we measured changes in fMRI responses before and after a five-day visual training protocol to determine the neuroplastic changes along the visual cascade. Fifty visually normal observers received training on a dichoptic or binocular variant of a signal-in-noise (left-right) motion discrimination task over five consecutive days. We show significant shifts in sensory eye dominance following training, but only for those who received dichoptic training. Pattern analysis of fMRI responses revealed that responses of V1 and hMT+ predicted sensory eye dominance for both groups, but only before training. After dichoptic (but not binocular) visual training, responses of V1 changed significantly, and were no longer able to predict sensory eye dominance. Our data suggest that perceptual training-driven changes in eye dominance are driven by a reweighting of the two eyes' data in the primary visual cortex. These findings may provide insight into developing region-targeted rehabilitative paradigms for the visually impaired, particularly those with severe binocular imbalance.

A role for ocular dominance in binocular integration.

Neurons in the primate primary visual cortex (V1) combine left- and right-eye information to form a binocular output. Controversy surrounds whether ocular dominance, the preference of these neurons for one eye over the other, is functionally relevant. Here, we demonstrate that ocular dominance impacts gain control during binocular combination. We recorded V1 spiking activity while monkeys passively viewed grating stimuli. Gratings were either presented to one eye (monocular), both eyes with the same contrasts (binocular balanced), or both eyes with different contrasts (binocular imbalanced). We found that contrast placed in a neuron's dominant eye was weighted more strongly than contrast placed in a neuron's non-dominant eye. This asymmetry covaried with neurons' ocular dominance. We then tested whether accounting for ocular dominance within divisive normalization improves the fit to neural data. We found that ocular dominance significantly improved model performance, with interocular normalization providing the best fits. These findings suggest that V1 ocular dominance is relevant for response normalization during binocular stimulation.

Invisible social grouping facilitates the recognition of individual faces.

Emerging evidence suggests a specialized mechanism supporting perceptual grouping of social entities. However, the stage at which social grouping is processed is unclear. Through four experiments, here we showed that participants' recognition of a visible face was facilitated by the presence of a second facing (thus forming a social grouping) relative to a nonfacing face, even when the second face was invisible. Using a monocular/dichoptic paradigm, we further found that the social grouping facilitation effect occurred when the two faces were presented dichoptically to different eyes rather than monocularly to the same eye, suggesting that social grouping relies on binocular rather than monocular neural channels. The above effects were not found for inverted face dyads, thereby ruling out the contribution of nonsocial factors. Taken together, these findings support the unconscious influence of social grouping on visual perception and suggest an early origin of social grouping processing in the visual pathway.

Amblyopia-A novel virtual round table to explore the caregiver perspective.

PURPOSE: A survey aimed to capture the caregiver's perspective on the impact of amblyopia and its treatment on the child and family, as well as caregivers' views on the design and feasibility of clinical trials investigating dichoptic binocular therapies for amblyopia. METHODS: Parents of amblyopic children, patient advocates and healthcare professionals took part in a moderated, structured discussion on a novel virtual advisory-board platform. RESULTS: Seven parents of children with amblyopia, two patient organisation representatives, one ophthalmologist and one optometrist participated in the survey. A total of 645 posts were entered on the platform over a 14-day period in September 2021. There was widespread agreement that the management of amblyopia poses more of a burden on the child and family than the condition itself, with treatment burden accentuated when treatment is unsuccessful. Parents expressed uncertainty and frustration in relation to the duration of patching, success of patching and alternative treatment options, and felt there was inadequate readily available, easy-to-understand information on the condition. Parents reported that a new treatment for amblyopia, such as dichoptic binocular therapy using video games, should be safe, non-invasive and engaging compared with an eye patch. Treating at home, potentially for a shorter treatment duration, and with an entertaining game were the main reasons parents would join a clinical study with this type of novel therapy. However, due to a limited critical period treatment window, parents would feel more comfortable joining a clinical trial if traditional therapies were offered in conjunction with those under investigation. CONCLUSION: Patient perspectives and the role of caregivers in the acceptance of any interventional treatments are increasingly recognised. Understanding how amblyopia and its treatment impacts a child and family should be an important premise to guide therapy and evaluate treatment value, both in clinical trials and in routine medical practice.

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.

Binocular vision therapy for the treatment of Amblyopia-A review.

Amblyopia is a monocular or binocular reduction in visual acuity that results from prolonged visual deprivation in the early years of life. It is second only to refractive error as a cause of poor vision in children. The gold standard treatment of amblyopia includes patching and, less commonly, atropine penalization and filters. These therapies are aimed at improvements in the visual acuity of the amblyopic eye alone. They have compliance and psychosocial issues and gains are accrued after prolonged periods. Experimental studies have demonstrated the presence of binocular cortical communication even in amblyopes and neural plasticity in late childhood as well as adulthood. On this basis, binocular vision therapy aimed at the stimulation of both eyes rather than forced use of the amblyopic eye was developed. Such therapies involve visual tasks designed in such a way that they can be completed only by binocular viewing. These tasks vary from simple game play using red-green glasses, to engaging 3D games and movie viewing. Preliminary data suggest that binocular vision therapy has led to lasting improvements in visual acuity and can be a useful adjunct, if not replacement, to the conventional treatment of amblyopia. In this article, we aim to describe the various binocular vision therapies and review the available literature on the same.

Acuity Comparison Methods via Timed Test-Retest Precision of Matching-Card e-ETDRS Compared to PDI Check in Treated Amblyopes and Superb Normals.

Purpose: Existing and emerging visual acuity methods like dynamic and dichoptic presentation, preferential looking and eye tracking promise to afford better and earlier assessment in children with and without amblyopia so we propose methods needed to easily evaluate and compare their metrics. Subjects and Methods: Patients older than 8 years with treated amblyopia and superb vision (logMAR -0.1 to -0.3) normals performed timed, patched eETDRS with Sloan matching card at 3.00 m and PDI Check dichoptic near rivalry dynamic test to demonstrate test re-Test and compared disparate acuity with intraclass correlation (ICC) and Bland Altman 95% limits of agreement (LOA) to generate a simple method of qualifying acuity test matching. Results: 26 amblyopic patients and 11 superb-vision normals performed eETDRS retest, PDI Check retest and combined ICC of 0.98, 0.60 and 0.27, respectively, and Bland Altman LOA of 0.24, 2.06 and 2.28 logMAR. The time to test one eye with eETDRS had median (interquartile range; IQR) duration of 280 (205 to 346) seconds, while the PDI Check autostereoscopic dichoptic for both eyes only took 39 (30 to 47) seconds. Optimum ICC and LOA for visual acuity comparison should be >0.95 and <0.3 logMAR, whereas "good" ICC and should be 0.75-0.89 ICC and 1.0-1.49 logMAR LOA. Conclusion: Superb vision subjects (logMAR < -0.1) and treated amblyopic patients confirmed optimum comparable eETDRS, and fair test re-Test PDI Check but suppression on near dichoptic testing confirmed disparity compared to optimized eETDRS distance acuity.

Stereoptic serious games as a visual rehabilitation tool for individuals with a residual amblyopia (AMBER trial): a protocol for a crossover randomized controlled trial.

BACKGROUND: Amblyopia is the most common developmental vision disorder in children. The initial treatment consists of refractive correction. When insufficient, occlusion therapy may further improve visual acuity. However, the challenges and compliance issues associated with occlusion therapy may result in treatment failure and residual amblyopia. Virtual reality (VR) games developed to improve visual function have shown positive preliminary results. The aim of this study is to determine the efficacy of these games to improve vision, attention, and motor skills in patients with residual amblyopia and identify brain-related changes. We hypothesize that a VR-based training with the suggested ingredients (3D cues and rich feedback), combined with increasing the difficulty level and the use of various games in a home-based environment is crucial for treatment efficacy of vision recovery, and may be particularly effective in children. METHODS: The AMBER study is a randomized, cross-over, controlled trial designed to assess the effect of binocular stimulation (VR-based stereoptic serious games) in individuals with residual amblyopia (n = 30, 6-35 years of age), compared to refractive correction on vision, selective attention and motor control skills. Additionally, they will be compared to a control group of age-matched healthy individuals (n = 30) to account for the unique benefit of VR-based serious games. All participants will play serious games 30 min per day, 5 days per week, for 8 weeks. The games are delivered with the Vivid Vision Home software. The amblyopic cohort will receive both treatments in a randomized order according to the type of amblyopia, while the control group will only receive the VR-based stereoscopic serious games. The primary outcome is visual acuity in the amblyopic eye. Secondary outcomes include stereoacuity, functional vision, cortical visual responses, selective attention, and motor control. The outcomes will be measured before and after each treatment with 8-week follow-up. DISCUSSION: The VR-based games used in this study have been conceived to deliver binocular visual stimulation tailored to the individual visual needs of the patient, which will potentially result in improved basic and functional vision skills as well as visual attention and motor control skills. TRIAL REGISTRATION: This protocol is registered on ClinicalTrials.gov (identifier: NCT05114252) and in the Swiss National Clinical Trials Portal (identifier: SNCTP000005024).

How do parents experience patching or dichoptic action video gaming as amblyopia treatment? A qualitative study exploring treatment preferences and information needs to facilitate decision-making.

PURPOSE: To explore parents' experiences, preferences and information needs when either patching treatment or dichoptic action video gaming is used as an amblyopia treatment for their child. METHODS: A qualitative study was carried out on parents whose newly diagnosed amblyopic children participated in a randomised controlled trial (RCT) comparing the effects of dichoptic action video gaming versus patching. A purposive heterogenic sample was selected for an additional interview after the study period. Semi-structured interviews were conducted with one or both parents and transcribed verbatim, and a thematic analysis was performed. RESULTS: Ten families agreed to participate: seven in the patching group and three in the gaming group. Two themes emerged from the data exploring experiences with treatment: (1) factors influencing compliance and (2) burden with treatment. Parents reported creating a routine which improved compliance with patching, as opposed to gaming where parents felt less need to conduct the treatment themselves as it was performed in the outpatient clinic. In both groups, parents experienced an information hiatus regarding the role of refractive error. In deciding the type of treatment to be used, parents preferred to deliberate the choice with the healthcare professional and discuss considerations resulting in shared decisions. The emerging themes were (1) effect and efficiency of treatment, (2) organisational aspects of treatments and (3) their child's traits. CONCLUSION: This study provides insight into the experiences of parents whose children underwent different types of amblyopia therapy. Both treatments have their own advantages and disadvantages. For parents, the effectiveness and efficiency of treatment were the most important aspects when deciding the method of management. Parents wish to come to a well-informed, shared decision regarding the type of amblyopia treatment.

Temporal synchrony discrimination is abnormal in dichoptic but not monocular visual processing in treated anisometropic amblyopes.

PURPOSE: To evaluate whether temporal synchrony processing deficits remain when normal visual acuity is restored in adults with unilateral anisometropic amblyopia. METHODS: We recruited 14 clinically treated anisometropic amblyopes (mean age 23.17 ± 2.53 years) with best-corrected visual acuity ≤ 0.1 logMAR and 15 age-matched emmetropes (mean age 24.40 ± 1.92 years) with normal vision to participate in our experiment. We presented two pairs of flicking Gaussian dots (1 Hz) as visual stimuli: one pair of dots was synchronous (reference), and the other pair of dots was asynchronous (signal). Subjects were asked to determine the position of the asynchronous pair. We applied the constant stimuli method to measure the temporal synchrony threshold under monocular and dichoptic viewing conditions. There were eight temporal phase lags in the asynchronous pair. The minimum degree of the temporal phase at which a participant can discriminate a signal pair is defined as the temporal synchrony threshold. RESULTS: Under monocular viewing conditions where both the reference and signal pairs were presented to one eye, the temporal synchrony thresholds of previous amblyopic eyes and fellow eyes were not significantly different (p = 0.15). Under dichoptic viewing conditions where both the reference and signal pairs were dichoptically presented to both eyes, the temporal synchrony threshold in the treated anisometropic amblyopes was significantly higher than that of the controls (119.34 ± 20.43 vs. 99.78 ± 16.60 ms, p = 0.009). There was no significant correlation between the monocular and dichoptic viewing conditions in the treated amblyopes (r = -0.22, p = 0.94). CONCLUSIONS: Temporal synchrony discrimination is abnormal under dichoptic but not under monocular visual stimulation in treated anisometropic amblyopes with normalised visual acuity.