Abstract
Purpose: :
Anisometropic amblyopia often improves with refractive correction alone. However, data are sparse regarding (1) the incidence of resolution of amblyopia, (2) the time course of visual acuity improvement, and (3) factors associated with resolution of amblyopia with spectacles alone.
Methods: :
In a prospective multicenter study, 84 children 3 to <7 years old with untreated anisometropic amblyopia (visual acuity 20/40 to 20/250) were treated with optimal refractive correction alone. Visual acuity was measured in a standardized manner, using HOTV optotypes and the Amblyopia Treatment Study protocol, with the new spectacle correction at baseline and at 5–week intervals until visual acuity stabilized or amblyopia resolved (interocular difference of 1 line or less). After stabilization, children with at least 2 lines of interocular difference were randomized to patching versus control in a second phase of the study.
Results: :
Of 84 children, amblyopia improved with optical correction alone by 2 or more logMAR lines in 65 (77%) and resolved in 23 (27%). Eleven (13%) wore spectacles for at least 20 weeks before stabilization criteria were met. Of 34 children followed in the control group during the study’s second phase, additional improvement occurred with spectacles alone in 21 (62%) and amblyopia resolved in 6 (18%). Treatment outcome was associated with better baseline visual acuity and with smaller amounts of anisometropia, but outcome was not associated with age.
Conclusions: :
In children 3 to <7 years old with no previous treatment, refractive correction alone improves visual acuity in most cases of anisometropic amblyopia and results in resolution of amblyopia in at least one–third. While most cases of resolution occur with moderate (20/40 to 20/100) amblyopia, those with denser (20/125 to 20/250) amblyopia also improve an average of 3 lines, which may lessen the burden of subsequent amblyopia therapy.
Keywords: amblyopia • spectacle lens • clinical (human) or epidemiologic studies: outcomes/complications