MAR 28, 2014
This prospective, randomized, multicenter study found that increasing daily patching from two hours to six hours can improve visual acuity results in children with stable residual amblyopia.
Subjects included 169 children aged 3 to 8 years with stable residual amblyopia (20/32 to 20/160) whose vision had stopped improving after 12 weeks of two-hour daily patching. They were randomized to continue two hours of daily patching or increase patching time to an average of six hours a day.
After 10 weeks, amblyopic eye visual acuity improved an average of 1.2 lines in the six-hour group and 0.5 lines in the two-hour group (P = 0.002). Improvement of two or more lines in the amblyopic eye at the best visit after randomization occurred in 51 percent of patients in the six-hour daily group and 18 percent of patients in the two-hour daily group. Patching compliance was judged to be good to excellent for 90 percent and 96 percent of participants in the six-hour and two-hour groups, respectively.
The authors write that given that so many of the children who continued the two-hour daily regimen still improved by two or more lines, it would not be unreasonable to continue this plan for at least another cycle even when vision seems to have stopped improving.
They conclude that the tactic of increasing patching when visual acuity seems to have stopped improving with lower-dose patching can now be incorporated into an evidence-based, stepwise management strategy for amblyopia. Amblyopia treatment can begin with spectacles alone, followed by a choice of low-dose patching, weekend atropine or a Bangerter filter. If significant amblyopia persists, it is reasonable to increase the dose of patching therapy.