Abstract
Purpose :
High-frequency flickering triggers post-receptoral response of the cone pathway, of which the central inner retinal electrical response was reported to be associated with refractive error development in school-aged children. This cross-sectional study aimed to investigate the interaction between refractive error and electroretinography (ERG) at two higher flickering frequencies in preschool children.
Methods :
A total of 197 preschool children aged between 3 and 7 years were examined. Ophthalmic assessments, including cycloplegic photorefraction, ocular biometry, and ERG measurements, were carried out. Refractive error, expressed as spherical equivalent power (SE), and axial length (AL) were measured. For flickering ERG, a customized protocol with 28.3 Hz and 37.6 Hz flickers was adopted using the RETeval portable ERG device with sensor strip skin electrodes.
Results :
The overall mean SE was +1.22 ± 1.01 D and the mean AL was 22.48 ± 0.74 mm. AL was positively correlated with age (r = 0.25, p <0.001) and male had a significantly longer AL than female (p <0.001). In contrast, SE was independent of age (p = 0.14) and gender (p = 0.71). The mean amplitude of 28.3 Hz and 37.6 Hz flickering ERG were 24.92 ± 4.93 µV and 28.80 ± 5.33 µV, respectively. The mean implicit time of 28.3 Hz and 37.6 Hz flickering ERG were 23.13 ± 0.44 ms and 23.76 ± 1.16 ms, respectively. Age was not a significant factor for neither the amplitude (p = 0.37) or implicit time (p = 0.70) of 37.6 Hz flickering ERG, nor the amplitude (p = 0.43) or implicit time (p = 0.07) of 28.3 Hz flickering ERG. Interestingly, the implicit time of 37.6 Hz flicker was more delayed in more myopia SE (r = -0.22; p <0.01), but was independent of 28.3 Hz flicker implicit time (p = 0.07). No correlation was found between SE and amplitudes of 37.6 Hz (p = 0.82) or 28.3 Hz flickers (p = 0.73).
Conclusions :
The post-receptoral response of the cone pathway was more delayed with more myopic refractive power in preschool children with the highest stimulating frequency at 37.6 Hz, but not 28.3 Hz. This may provide further insight into the subclinical temporal interaction impairment in the retina which appeared early in life.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.