Effects of Different Spectrum of LEDs on Retinal Degeneration Through Regulating Endoplasmic Reticulum Stress.

Abstract

To evaluate the impact of full-spectrum light-emitting diodes (LEDs) on albino guinea pigs' retina and investigate the roles of short-wavelength opsin (S-opsin) and endoplasmic reticulum (ER) stress in light-induced retinal degeneration (LIRD). Three-week-old albino guinea pigs (n = 30) were distributed into five groups under 12/12 light/dark cycles with indoor natural light (NC; 300-500 lux, n = 6), full-spectrum LEDs (FL; 300 lux, n = 6; 3000 lux, n = 6), and commercial cold-white LEDs (CL; 300 lux, n = 6; 3000 lux, n = 6) and raised for 28 days. Hematoxylin and eosin staining and transmission electron microscopy evaluated the morphological changes of retinas. The immunofluorescence and real-time quantitative polymerase chain reaction (RT-qPCR) measured the expression and content of S-opsin and ER stress-related genes and proteins. We found that albino guinea pigs exposed to FL at either 300 lux or 3000 lux developed less severe retinal morphological damage than animals exposed to the CL light, which emerged as a significant characteristic of LIRD. Meanwhile, the damage on the ventral retina was more serious, mainly due to its ability to absorb the blue light in the LEDs more easily. Compared to the FL-exposed groups, the CL light increased the aggregation of S-opsin and the expression of ER stress-related factors. Commercial cold-white LEDs can induce ER stress and unfolded protein response in LIRD, and full-spectrum LED attenuates LIRD by regulating ER stress in albino guinea pig retinas in vivo. Full-spectrum LEDs offer specific eye protection and eye adaptability that can well replace commercial cold-white LEDs in both clinical practice and research. It should be further developed for lighting used in health care facilities.