Age-dependencies of the electroretinogram in healthy subjects

Objective

The purpose of this study was to evaluate the age-dependency of amplitudes and implicit times in the electroretinograms (ERGs) of healthy individuals and provide clinicians and researchers with a reference for a variety of stimulus paradigms.

Design and methods

Full-field electroretinography was conducted on 73 healthy participants aged 14–73 using an extended ISCEV standard protocol that included an additional 9 Hz flicker stimulus for assessing rod function and special paradigms for isolated On–Off and S-cone responses. Correlation coefficients and best-fit regression models for each parameter’s age-dependency were calculated.

Results

Dark-adapted ERGs, in particular, displayed notable age-related alterations. The attenuation and delay of the b-wave with higher age were most significant in the dark-adapted, rod-driven 0.001 cd s/m² flash ERG. The age-dependent reduction of the a-wave amplitude was strongest in the standard dark-adapted 3 cd s/m² flash condition. Cone-driven, light-adapted responses to either flash or flicker stimuli displayed comparatively small alterations at higher age. S-cone function tended to diminish at an early age, but the effect was not significant in the whole population.

Conclusion

The results suggest that rod and cone function decline at different rates with age, with rods being generally more affected by aging. Nonetheless, response amplitudes displayed a wide variability across the whole sample.