Accessible LED Lightbox for Light-induced Retinal Damage in Pigmented Mice

PURPOSE. To design and validate a cost-effective and titratable system capable of light- induced photoreceptor dysfunction and damage in pigmented mice. METHODS. Two commonly used mouse strains in vision research, C57BL/6J and 129SVE mice, were exposed individually to varying light intensities in custom-designed boxes. Visual function was assessed by ERG, which was conducted two days prior, one day, and one week after light exposure. For morphological evaluation of photoreceptor health, we stained retinal sections with hematoxylin and eosin followed by light microscopy. Photoreceptor nuclei were quantified at equidistant points across the entire retina. RESULTS. C57BL/6J and 129SVE mice exhibited a significant reduction in visual function 1 day after exposure to light at varying light intensities from 10 to 60 klx for 4 hours. We observed a loss in visual function 1 day after exposure that correlated with the light intensity. The visual function did not recover even at 7 days after exposure. We observed loss of photoreceptor nuclei with regional differences in susceptibility to light damage, with the central retina being more affected than the periphery. CONCLUSIONS. The lightbox system we developed effectively reduced visual function in pigmented animals after 4 hours of light exposure. Additionally, the system is flexible; the intensity and duration of light exposure can be adjusted to induce a desired level of light-induced photoreceptor dysfunction and damage.