Myopia progression in children is linked with reduced foveal mfERG response

Purpose. To study the changes in retinal electrophysiology in children during myopia progression during a 1-year period. Methods. Twenty-six children aged from 9 to 13 years were recruited for the global flash multifocal electroretinogram (mfERG) measured at 49% and 96% contrast, in two visits 1 year apart. The amplitudes and implicit times of both direct component (DC) and induced component (IC) measured at these two visits were analyzed and compared. Pearson's correlation was used to study the association between the changes of mfERG response and myopia progression during the test period. Results. Myopia increased by -0.48 ± 0.32 diopter (D) (P < 0.001) during the year, with 24 of 26 children becoming more myopic (range = 0.00 to ~ -1.38 D); axial length increased by 0.25 ± 0.11 mm (P < 0.001) during the year. The increased myopia was highly correlated with increase in axial length (r = -0.70; P < 0.001). The central DC and IC amplitudes at 49% contrast reduced significantly as myopia progressed and the paracentral implicit times of these two components were reduced considerably. However, the high-contrast responses were virtually unaffected. Conclusions. Our findings suggested that the inner retinal functions in the central retina, with some involvement of the paracentral region, were decreased as myopia progressed in children.