A consideration of binocular parameters in the spectacle correction of anisometropic amblyopia: A Case Report

Background: Recent evidence points to the use of spectacles alone in the treatment of anisometropic amblyopia. However, the impact of this treatment on the restoration of binocular vision is often not considered. Case Report: Patient M.Z., aged 7 years, showed 3.5D of anisometropia which was coupled with a best corrected visual acuity of 6/38 in the more hyperopic eye (6/6 in the non-amblyopic eye). Spectacle lenses were prescribed using specially designed software to alter the spectacle frame and lens parameters to theoretically reduce the static and dynamic aniseikonia to 1% and 3.8% respectively. Four subsequent follow up visits were conducted over a 2 year period where standard clinical measures of refraction, visual acuity, and binocular vision were conducted. The spectacles were worn consistently over this time. Single letter acuity normalized by 5 months while crowded acuity took longer. Improvements of binocular vision resulted concomitantly. However, improvement in suppression and stereo acuity contin ued for 2 years following the initial spectacle correction. Conclusions: This case exemplifies how the prescribing of spectacle lenses with consideration of, and correction for, predicted optical aniseikonia allowed the amelioration of amblyopia without patching and the provision of significant levels of binocular vision within a 1 year period. However, the time course for the development of binocular vision well exceeded that for the amelioration of amblyopia.