Patch-free streaming contrast-rebalanced dichoptic cartoons versus patching for treatment of amblyopia in children aged 3 to 5 years: a pilot, randomized clinical trial

Abstract

Background: We developed and tested a dichoptic treatment designed for younger children that can be viewed freely and involves a dichoptic manipulation of a popular animation series that enables contrast-rebalancing without disrupting fusion. Our aim was to assess whether this novel amblyopia treatment is superior to patching in children aged 3-5 years.

Methods: A total of 34 children with amblyopia were randomly assigned to contrast-rebalanced dichoptic cartoons (4 hours/week) or patching (14 hours/week) for 2 weeks. Children in the cartoon group continued watching cartoons for an additional 2 weeks. Designed to target the youngest and most treatable children, the dichoptic cartoons presented the entire scene to the amblyopic eye at 100% contrast, while the fellow eye view was presented at reduced contrast with the main character omitted. Best-corrected visual acuity (BCVA), stereoacuity, suppression, and manual dexterity were measured at each visit.

Results: After 2 weeks, improvement in amblyopic eye BCVA was greater for dichoptic treatment than for patching, with a mean improvement of 0.11 ± 0.08 versus 0.06 ± 0.09 logMAR, respectively (P = 0.04). Stereoacuity, suppression, and manual dexterity did not improve significantly more in the dichoptic group than the patching group at 2 weeks. After 4 weeks of dichoptic cartoon treatment, mean visual acuity improvement in the dichoptic group was 0.16 logMAR (95% CI, 0.10-0.21).

Conclusions: In our study cohort, a contrast-rebalanced dichoptic cartoon was more effective than patching in treating childhood amblyopia after 2 weeks. Dichoptic cartoons that rebalance contrast to overcome suppression provide an additional treatment option for amblyopia in young children.

FIG 1.

Consolidated standards of reporting trials (CONSORT) diagram. Shown are the numbers of assessed, excluded, analyzed, dropped, and missed visits during the 4 week study. Two children dropped the study, refusing to watch the videos at home. BCVA, best-corrected cvsual acuity.

FIG 2.

Dichoptic presentations of Q Pootle 5. A, Left side is the presentation at lower contrast (29%, day 5 of treatment) that is seen by the fellow eye. It is missing the green alien and lamp shades. Right side is the presentation at 100% contrast to the amblyopic eye with all characters and elements present. The two views are superimposed during viewing of the dichoptic cartoon for amblyopia treatment. B, Left side is the presentation at lower contrast (43%, day 9 of treatment) that is seen by the fellow eye. It is missing the yellow alien and water pail. Right side is the presentation of 100% contrast to the amblyopic eye with all characters and elements present. The two views are superimposed during viewing of the dichoptic cartoon for amblyopia treatment.

FIG 3.

BCVA at baseline, the 2-week visit, and the 4-week visit. Shown as the solid line with black circles is the amblyopic eye BCVA improvement for the dichoptic cartoons group after 2 weeks and 4 weeks of treatment. Shown as the dashed line with white circles is the amblyopic eye BCVA improvement for the patching group after 2 weeks of treatment. Error bars represent standard errors.