Abstract
Purpose :
Blue light hazard refers to potential retinal phototoxicity from short-wavelength “blue” light exposure. Blue light is ubiquitous in both natural and artificial light sources, including, most notably, sunlight. Light emitting diodes (LEDs) are a common source of artificial blue light. Speculation exists whether blue light from LED-backlit electronic devices may lead to retinal toxicity. The purpose of this study was to determine the effects of long-term exposure to narrowband short-wavelength ambient lighting on retinal function in rhesus monkeys that were part of experiments examining the effects of blue light on refractive development (Hung et al., 2021).
Methods :
Infant rhesus monkeys were reared under short-wavelength “blue” light (n=7; 465 nm, 20 nm half-max bandwidth;183±28 lux) on a 12-hour light/dark cycle starting at 26±2 days of age. Age-matched control monkeys were reared under broadband “white” light (n=8; 504±168 lux). Light- and dark-adapted full-field flash electroretinograms (ERGs) were recorded in anesthetized monkeys at 330±9 days of age. Photopic stimuli were brief duration (<5 ms) red flashes (0.04-5.68 cd.s/m2) on a rod-saturating blue background and the ISCEV standard white flash (3.0 cd.s/m2 on a white 30 cd/m2 background). Monkeys were dark-adapted for 20 minutes and scotopic stimuli were ISCEV standard white flashes of 0.01, 3, and 10 cd.s/m2. A-wave, b-wave, and photopic negative response (PhNR) amplitudes were measured.
Results :
For ISCEV standard light-adapted ERGs, there were no significant differences in a-wave (43.1±9.6 vs. 39.9±4.4 µV; P=0.35), b-wave (176.1±40.1 vs. 160.1±30.6 µV; P=0.49), and PhNR (16.4±8.7 vs. 8.7±10.0 µV; P=0.15) amplitudes between control and blue light reared monkeys. For red flashes on a blue background, there were no significant differences in a-wave, b-wave, and PhNR amplitudes between groups for all flash energies (P>0.05 for all). Similarly, dark-adapted a- and b-wave amplitudes were not significantly different between groups (P>0.05 for all). There were no significant differences in a- and b-wave implicit times between groups for all ISCEV standard stimuli (P>0.05 for all).
Conclusions :
Long-term exposure to narrowband blue light did not affect photopic or scotopic ERG responses in infant monkeys. Findings suggest that exposure to 12 hours of daily blue light for approximately 10 months does not result in altered retinal function.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.