Treating anisometropic amblyopia with a dichoptic digital platform

The Bynocs online platform includes a variety of games based on dichoptic stimulation and using different environments, which allows children to play while an effective stimulation is performed. Image credit: ©Natcharlai – stock.adobe.com

A recent study found that dichoptic training, a relatively new therapy for treating amblyopia, achieved improved visual acuity (VA) and binocularity in both children and adults with anisometropic amblyopia using a digital platform,¹ according to first study author Carolina Picotti, MD. She is from the Hospital Regional Louis Pasteur Villa María, Cordoba, Argentina.

The investigators explained this therapeutic option provides a simultaneous and separate stimulation of both eyes to eliminate the interocular suppression, which has a primary role in the development of amblyopia.² The contrast in the eye without amblyopia is decreased during stimulation to achieve a balance with the eye with amblyopia. The interruption or weakening of binocular vision during childhood due to a factor such as anisometropia can promote different levels of interocular suppression that are associated with different levels of reduction in the VA.³

The authors conducted a prospective noncomparative study to evaluate dichoptic training for amblyopic patients over a large age range. A total of 41 patients with anisometropic amblyopia, who ranged in age from 6 to 60 years, were evaluated. Participants were divided into 2 groups based on age. Children were defined as ranging in age from 6 to 16 years (n = 24) and adults were over 17 years of age (n = 17). According to Dr Picotti, all patients were treated with the Bynocs platform (Kanohi Eye Pvt. Ltd.). Each session was conducted for 30 minutes 5 times a week for 6 weeks. The platform called for a protocol of 30 sessions.

The Bynocs online platform includes a variety of games based on dichoptic stimulation and using different environments. This approach allows children to play while an effective stimulation is performed, the researchers explained.

During the first 10 sessions, the dichoptic exercises included scenes that were mostly seen by the dominant eye (use of red-blue goggles for dissociation), while 1 crucial stimulus for game performance was only seen by the nondominant eye.

When this part of the therapy concluded, stereopsis and fusional vergence exercises were included in daily training protocol. The size of the stimuli and the duration of each exercise (maintaining a total training time of 30 minutes) could be modified according to the level of progression of the patient.

Stimulation results

The investigators found that the corrected distance visual acuity (CDVA) in the amblyopic eye improved significantly in all patients regardless of age. Specifically, they reporteda significant (P < .001) mean change of 0.30 in the logarithm of the minimum angle of resolution VA; the change in the CDVA was correlated significantly with the baseline CDVA in the amblyopic eye (r = –.568, P < .001). The authors also reported a significant (P < .001) improvement in the binocular function score of 1.14 log units after treatment.

Group comparison

When the results in the paediatric group were compared with the adult group, no significant differences were found in the changes achieved with therapy in CDVA (P = .431) and binocular function(P = .760).

The authors concluded, “Dichoptic training with the digital platform evaluated provides an effective improvement of VA and binocular function in children and adults with anisometropic amblyopia.”

They also offered some caveats. “This study was conducted in a sample of Argentinian children and adults, and the results obtained should be considered with care and confirmed in other samples including people from different ethnic groups to confirm if the effect of amblyopia treatment is affected or not by ethnicity. To this date, the efficacy of this option of treatment has been also confirmed in a paediatric population from India."⁴

References

1. Picotti C, Fernández Irigaray L, Del Rivero A, Fariñalas M, Piñero DP. Treatment of anisometropic amblyopia with a dichoptic digital platform in Argentinian children and adults. Semin Ophthalmol. https://doi.org/10.1080/08820538.2023.2243323

2. Hess RF, Mansouri B, Thompson B. A binocular approach to treating amblyopia: antisuppression therapy. Optom Vis Sci. 2010; 87: 697-704

3. Li J, Thompson B, Lam CS, et al. The role of suppression in amblyopia.Invest Ophthalmol Vis Sci. 2011;52:4169-4176

4. Abdal O, Bhombal F, Nankani GJ, et al. Evaluation of the efficacy of a new dichoptic digital platform to treat the anisometropic and isometropic amblyopia. Brain Sci. 2022; 12: 815