The purpose of the study is to determine whether a patch-free occlusion therapy leads to better visual outcomes in young children with amblyopia than standard-of-care occlusion therapy with an adhesive patch and whether this is associated with better adherence to the treatment.

This is a single-site randomized clinical trial to compare patch-free occlusion therapy with standard-of-care occlusion therapy with an adhesive patch in young children with amblyopia. Participants will be referred from local pediatric ophthalmologists. Following informed consent, children will complete baseline testing to confirm eligibility and provide pre-treatment measurements of visual acuity, suppression, stereoacuity, motor skills, self-perception, and quality of life. Eligible children will then be randomly allocated to either patch-free occlusion therapy or standard-of-care occlusion therapy with an adhesive patch.

Children will participate in their assigned occlusion therapy at home for 12 weeks (primary outcome). Adherence will be objectively monitored with a Theramon sensor. Vision will be re-assessed at 6 weeks and all tests will be repeated at 12 weeks. The patch-free occlusion group will have an option to continue the patch-free occlusion for and additional 6 or 12 weeks (24 weeks total). The standard-of-care occlusion group will be offered the opportunity to use the patch-free treatment at the 12 week visit through 24 weeks. Children who choose to remain in the study beyond the 12 week primary outcome visit will have vision reassessed at 18 and 24 weeks.

The primary analysis will be a comparison of improvement in amblyopic eye visual acuity (baseline-12 weeks) between the patch-free occlusion group and the standard-of-care patching group. Secondary analyses will include comparisons adherence to each treatment, comparison of the proportion of children in each group with visual acuity ≤0.1 logMAR (recovered) at 6 and 12 weeks visit and 95% CIs (at 6 and 12 weeks), comparisons of changes in extent of suppression, depth of suppression, stereoacuity, motor skills standard scores, self-perception scores, and PedEyeQ domain scores. Associations among hours of treatment, changes in visual acuity, suppression, and stereoacuity, will be explored and modeled for dose-response relationships. In exploratory analyses, we will examine whether there are additional improvements in visual acuity, suppression, or stereoacuity between 12 and 24 weeks for the patch-free group (12, 18, and 24 weeks means and 95% CIs).

Inclusion Criteria:

• 3-12 years
• male and female
• strabismic, anisometropic, or combined mechanism amblyopia (visual acuity: 0.3-0.8 logMAR)
• interocular visual acuity difference ≥0.3 logMAR
• wearing glasses (if needed) for a minimum of 8 weeks with no change in visual acuity at 2 visits ≥4 weeks apart
• child's ophthalmologist and family willing to forgo standard patching treatment during the study

Exclusion Criteria:

• Prematurity ≥8 wk
• coexisting ocular or systemic disease
• developmental delay
• myopia > -3.00D