Movement hyperacuity deficit in childhood amblyopia

Besides a loss in resolution acuity, amblyopia results in deficits in a number of visual functions in the amblyopic eye. We describe impairment in oscillatory movement displacement thresholds (OMDT) in childhood amblyopia. 50 subjects (aged 74 ± 16 months) with strabismic, anisometropic or mixed aetiology amblyopia were compared to a group of 24 age‐matched controls. Thresholds were demonstrated to be in the hyperacuity range and were not related to the visual acuity. OMDT was significantly reduced in the amblyopic eye compared to the dominant and control eyes ( P < 0.05) only when no stereoscopic responses were demonstrated. When gross stereopsis was present, thresholds for the amblyopic eyes were comparable with both the dominant and control eyes. The results are discussed in terms of binocular competition and developmental anomaly.