Objective: To compare full-time patching (all hours or all but 1 hour per day) to 6 hours of patching per day, as prescribed treatments for severe amblyopia in children younger than 7 years.
Design: Prospective, randomized multicenter clinical trial (32 sites).
Participants: One hundred seventy-five children younger than 7 years with amblyopia in the range of 20/100 to 20/400.
Intervention: Randomization either to full-time patching or to 6 hours of patching per day, each combined with at least 1 hour of near-visual activities during patching.
Main outcome measure: Visual acuity in the amblyopic eye after 4 months.
Results: Visual acuity in the amblyopic eye improved a similar amount in both groups. The improvement in the amblyopic eye acuity from baseline to 4 months averaged 4.8 lines in the 6-hour group and 4.7 lines in the full-time group (P = 0.45).
Conclusion: Six hours of prescribed daily patching produces an improvement in visual acuity that is of similar magnitude to the improvement produced by prescribed full-time patching in treating severe amblyopia in children 3 to less than 7 years of age.