Contrast-Rebalanced Binocular Amblyopia Treatment May Improve Manual Dexterity

Pediatric patients with amblyopia may demonstrate manual dexterity improvements following contrast-rebalanced treatment, according to a study published in the Journal of the American Association for Pediatric Ophthalmology and Strabismus. However, their manual dexterity scores, as measured by the Movement Assessment Battery for Children–2, are still significantly lower than those achieved by children without amblyopia.  

Researchers at the Retina Foundation of the Southwest included 134 children with anisometropic, strabismic, or combined mechanism amblyopia in the investigation and administered treatment with contrast-rebalanced binocular games (63%) or contrast-rebalanced videos (37%) during a 4- to 8-week duration. Participants were stratified according to age (age 3 to younger than 7 years: n=75; ages 7-10 years: n=59) and outcomes were compared with control group participants (n=20 for each age group).

Treatment improved visual acuity by an average of 0.14 logarithm of the minimum angle of resolution (logMAR; P <.0001), the report shows. Stratified by age, children aged 3 to less than 7 years had a mean visual acuity improvement of 0.16 logMAR (P <.0001), while children aged 7 to 10 years improved by a mean 0.13 logMAR (P <.0001) from baseline.

Overall, 85% of children experienced improvements in visual acuity. Compared with baseline, more children demonstrated fusion in the Worth 4-Dot test (76% vs 86%), severity of suppression in the Contrast Balance Index improved (6.9 vs 5.5), and the percentage of participants without stereoacuity decreased (83% vs 67%) following treatment (P <.0001 for all).

Manual dexterity scores at baseline were lower among patients with amblyopia compared with control group participants in both children aged 3 to younger than 7  years (8.81 vs 11.80; P <.0001) and those aged 7 to 10 years (7.19 vs 9.75; P =.0003). These scores improved by 0.98 among children with amblyopia following treatment (P <.0001). Stratified by age, both individuals aged 3 to younger than 7 years and children aged 7 to 10 years experienced improvements from baseline, but scores remained lower compared with control group participants (P ≤.03 for both). The level of improvement did not differ on the basis of age (P =.58).

Manual dexterity improvement was positively associated with visual acuity and improved by 1.50 among children with a 0.2 to 0.5 logMAR visual acuity improvement compared with 0.63 among those with a 0.1 logMAR improvement (P =.006).

The change in manual dexterity score was not dependent on stereoacuity, fusion, or suppression, the report shows.

“Early childhood is a key period for the development of manual dexterity,” according to the researchers. “Poor manual dexterity has been associated with anxiety, lower self-esteem, and academic difficulties. Because vision plays an essential role in guiding online control of developing eye-hand coordination, early intervention to minimize visual impairment may be beneficial.”

Study limitations include a failure to include children with amblyopia who were treated with atropine, patching, or observation.