Long-term blue light rearing does not affect in vivo retinal function in young rhesus monkeys.

Abstract

Exposure to blue light is thought to be harmful to the retina. The purpose of this study was to determine the effects of long-term exposure to narrowband blue light on retinal function in rhesus monkeys. Young rhesus monkeys were reared under short-wavelength "blue" light (n = 7; 465nm, 183 ± 28lx) on a 12-h light/dark cycle starting at 26 ± 2days of age. Age-matched control monkeys were reared under broadband "white" light (n = 8; 504 ± 168lx). Light- and dark-adapted full-field flash electroretinograms (ERGs) were recorded at 330 ± 9days of age. Photopic stimuli were brief red flashes (0.044-5.68cd.s/m2) on a rod-saturating blue background and the International Society for Clinical Electrophysiology of Vision (ISCEV) standard 3.0 white flash on a 30cd/m2 white background. Monkeys were dark adapted for 20min and scotopic stimuli were ISCEV standard white flashes of 0.01, 3.0, and 10cd.s/m2. A-wave, b-wave, and photopic negative response (PhNR) amplitudes were measured. Light-adapted ERGs in young monkeys were compared to ERGs in adult monkeys reared in white light (n = 10; 4.91 ± 0.88years of age). For red flashes on a blue background, there were no significant differences in a-wave (P = 0.46), b-wave (P = 0.75), and PhNR amplitudes (P = 0.94) between white light and blue light reared monkeys for all stimulus energies. ISCEV standard light- and 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). PhNR amplitudes of young monkeys were significantly smaller compared to adult monkeys for all stimulus energies (P < 0.05 for all). There were no significant differences in a-wave (P = 0.19) and b-wave (P = 0.17) amplitudes between young and adult white light reared monkeys. Long-term exposure to narrowband blue light did not affect photopic or scotopic ERG responses in young monkeys. Findings suggest that exposure to 12h of daily blue light for approximately 10months does not result in altered retinal function.