Associations of light-adapted electroretinogram in paediatric amblyopia

The aim of this study was to investigate changes in the light-adapted (LA) electroretinogram (ERG) associated with paediatric amblyopia.

A total of 220 eyes from 81 postoperative paediatric cataract patients and 29 healthy children were enrolled in four groups, namely controls, unilaterally amblyopic eyes, non-amblyopic fellow eyes and bilaterally affected eyes. Differences in LA ERG variables (peak time and amplitude of a- and b-waves and photopic negative response [PhNR]) were compared across groups, as well as their associations with visual acuity and changes in axial length.

The peak time of both the a-wave (p < 0.001) and b-wave (p < 0.001), as well as the amplitude of the b-wave (p < 0.001) and the PhNR (p = 0.04) differed significantly across groups. Compared to controls, affected eyes in both unilateral and bilateral groups showed significantly lower b-wave amplitude and longer a- and b-wave peak times (p < 0.008, Bonferroni-corrected). Additionally, fellow eyes in the unilateral group exhibited significantly longer b-wave peak times (p = 0.008). For all eyes, poorer visual acuity was associated with a longer peak time for both the a- (p = 0.006) and b-waves (p = 0.003), as well as lower amplitudes of the b-wave (p = 0.006) and PhNR (p = 0.02).

Changes in LA ERG components suggest alteration of retinal physiology in deprivation amblyopia. Thus, the LA ERG may provide additional information to help understand the mechanisms underlying deprivation amblyopia.