Electroretinogram to flickering light after exposure to bright and dim light conditions during the day

Abstract

Bright light has been known to have an impact circadian system in human. For example, bright light at the night can suppress melatonin secretion, whereas it at the morning can prevent light-induced melatonin suppression at the night. The preventing effect of the morning light might be involved a diurnal variation of an as intrinsically photosensitive retinal ganglion cells ‹ ipRGCs›, which regulates the circadian system. In this study, we evaluated electroretinogram ‹ERG› to the red and blue flickering light after exposure to bright and dim light conditions during the day. Twelve healthy females from 21 to 23 years old were measured ERG during exposed 30 Hz flickering light at the morning and the evening. Although there was no significant difference on the amplitude of ERG to the red light between bright and dim light conditions at the day, the amplitude to the blue light on the bright light condition at the day was significantly decreased compared to that on the dim light condition. As ipRGCs are most sensitive to the blue light, present findings suggest bright light during the daytime can attenuate a sensitivity of ipRGCs.