Evaluation of the Efficacy of a New Dichoptic Digital Platform to Treat the Anisometropic and Isometropic Amblyopia

Effectiveness of Dichoptic Therapy for Treating Mild to Moderate Amblyopia in a Tertiary Eye Care Center in South India

PURPOSE

To contribute evidence about the effectiveness of dichoptic therapy in patients with mild to moderate amblyopia.

METHODS

A retrospective study was conducted in patients enrolled for dichoptic therapy on the Bynocs AmblyGo platform (Kanohi Eye Pvt Ltd) from January to August 2023. Data collected included logarithm of the minimum angle of resolution best corrected visual acuity, anterior and posterior segment examination, fixation pattern, dynamic and cycloplegic refraction, orthoptic evaluation, and number of dichoptic therapy sessions. Visual acuity, binocularity, and stereopsis before and after therapy were analyzed.

RESULTS

Of 59 patients (median age: 11 years, range: 5 to 30 years) enrolled, 34 (57.6%) had anisometropic amblyopia, 12 (20.3%) had ametropic amblyopia, 10 (17.0%) had strabismic amblyopia, and 3 (5.1%) had deprivation amblyopia. All 6 (10.2%) and 15 (22.4%) patients who had no binocular single vision for near and distance before therapy, respectively, attained normal binocular single vision on completion, except one who suppressed at distance. Twenty-one (75.0%) had improved near stereopsis, and 21 (60.0%) had improved distance stereopsis. Of 74 eyes treated, 61 (82.4%) had improved visual acuity and 73 (98.6%) improved in at least one tested parameter. A majority of these eyes had residual amblyopia after occlusion therapy.

CONCLUSIONS

Dichoptic therapy improves visual acuity, binocularity, and stereoacuity in patients with amblyopia, including those older than 8 years, especially in partial deprivation, ametropic, and anisometropic amblyopia. {J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XX-XX.].

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.

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.

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.

Binocular vision measurements with a new online digital platform: comparison with conventional clinical measures

CLINICAL RELEVANCE

New digital systems are being developed for evaluating different aspects of the visual function, such as binocularity, and it is important to know their real performance in clinical practice in order to use them appropriately.

BACKGROUND

The aim was to compare binocular vision measures obtained with an online digital platform with conventional measures using prisms and printed tests.

METHODS

Prospective study enrolling 49 healthy patients (mean age: 35.5 ± 13.6 years). A complete visual examination was performed including measurement of near phoria (cover test), negative fusional vergence (NFV) and positive fusional vergence (PFV) ranges (prism bar), and stereopsis (24 patients Randot Stereo Test and 25 patients TNO Random Dot Test 19th edition). These same parameters were also measured with the Bynocs system (Kanohi Eye Pvt Ltd). Bland - Altman plots were used to analyse the agreement between methods.

RESULTS

Digital measurement of near phoria was significantly lower than that obtained with the cover test, with a median difference (MD) of 4.71 (-0.07-20.07) prism dioptres (pd) (p < 0.001). No significant differences were found between Bynocs and prism bar methods in NFV break (MD 2.00, range -21-26 pd, p = 0.584) and recovery points (MD 0.00, range -16-24 pd, p = .571). Near PFV were significantly lower with Bynocs (break: MD -9.00, range -38-12 pd; recovery: MD -14.00, range -43-20 pd; p < 0.001). Bynocs stereoacuity threshold was significantly lower than that obtained with TNO (p = 0.004), but significantly higher compared to Randot (p < 0.001). Large and clinically relevant confidence intervals for the comparison between digital and conventional measures were detected in Passing-Bablok analysis.

CONCLUSIONS

Digital measures of near phoria, NFV, PFV, and stereopsis with the Bynocs platform cannot be used interchangeably with conventional measures. The normal ranges of normality for this new tool are defined.