We appreciate Dr Phillips' thoughtful evaluation of our trial in which children aged 7 to 17 years with amblyopia (visual acuities of 20/40-20/400) were randomized either to a treatment regimen consisting of optical correction, patching, and atropine or to optical correction alone. A patient who improved 10 or more letters on an ETDRS scale was considered a responder. Dr Phillips suggests that the benefit of treatment was greater in the patients with anisometropic amblyopia than in those with strabismic amblyopia and that the approach to management might therefore differ according to cause. In actuality, although the patients with anisometropic amblyopia appeared to show greater improvement than those with strabismic amblyopia in both treatment groups (although these differences were not statistically significant after adjusting for the confounding effect of age, baseline acuity, prior treatment of amblyopia, and prior spectacle wear), the relative treatment effect was remarkably similar for both causes of amblyopia. The risk ratio for being a responder was 2.1 for both strabismic and anisometropic amblyopia, and for the 2 secondary outcomes reported, maximum improvement and interocular difference, the relative treatment effects were similar (for interaction, P = .72 and .14, respectively). Thus, our results do not provide support for prescribing differing treatment regimens for strabismic amblyopia and anisometropic amblyopia.
Scheiman MM, Hertle RW, Beck RW, Edwards AR, Birch E, Cotter SA, Crouch ER, Cruz OA, Davitt BV, Donahue S, Holmes JM, Lyon DW, Repka MX, Sala NA, Silbert DI, Suh DW, Tamkins SM, for the Pediatric Eye Disease Investigator Group. Amblyopia in Children Aged 7 to 17 Years—Reply. Arch Ophthalmol. 2006;124(11):1668-1669. doi:10.1001/archopht.124.11.1668-b