Full-field electroretinogram findings in children in the atropine treatment for myopia (ATOM2) study

Abstract

The aims of this study were to determine the longitudinal effects of myopia on full-field electroretinogram (ffERG) in children, and whether there were any effects due to atropine treatment. Fifty children, enrolled in the atropine treatment for myopia study, were randomly selected and 35 children consented to undergo ffERG at baseline (prior to atropine treatment), 24 months (at end of treatment) and 32 months (8 months after cessation of treatment). An extended ISCEV ffERG protocol was used for all recordings. The relationship between axial length (AL) and the following scotopic and photopic ffERG responses was analyzed: a- and b-wave amplitude and implicit time, saturated amplitude (V max), and retinal sensitivity (logK). Reliable ffERG recordings with acceptable level of noise were obtained on all 3 visits from 29 children (mean age: 9.5 ± 0.8 years and mean spherical equivalent: -5.0 ± 1.6 D). At baseline, the correlation detected between AL and logK was 0.37 (p = 0.047). There was no significant correlation between AL and V max or any scotopic and photopic ffERG amplitude and implicit time measures. Longitudinal data suggested a reduction in photopic a- and b-wave and 30 Hz flicker response amplitudes over time. Multivariate analysis showed that the change in 30 Hz flicker response amplitude was likely to be associated with AL change. There was no evidence that changes in other responses were associated with age, baseline AL, or atropine dose used. Retinal sensitivity was reduced in myopic children. There was a gradual decline in cone function over time which was not influenced by atropine treatment.