The Function Of Green Reflected Light In Lessening Retinal Light Damage

Objective:Make a light box using the green paper and white paper of the teaching materials as background, thus setting up an optical damage model. This paper is to discuss the effect of green reflection on the retinal light damage, as well as whether the green light and its reflection can alleviate retinal light damage, so as to change people’s ideas that green light and its reflection can protect the retina, and explore the precautions against retinal degeneration diseases.Methods:Equally divide96healthy adult male Sprague-Dawleys (weigh between180—220g with no eye diseases) into four groups:normal control, retinal light damage, green reflection and white reflection. The light box has an outer layer, a light shelf in between and a mouse cage inside. In the green reflection group, put the green paper on the inner side of the outer layer, white paper in the white reflection group, transparent glass in the retinal light damage group, and no treatment for the normal control. The light boxes have exhaust holes with a constant temperature of25℃and the same light source, the center illumination is2800Lux. All the mice spend seven days with the alternating cycle of12hours light and12hours darkness, and then24hours darkness to improve the photosensitivity of retina.20minutes before light, give the mice atropine eye drops to fully dilate the pupils. Then put them into the light boxes for24hours of continual light from8:00am. They should be given plenty of food and water during this period. Then24hours of darkness and take the retinas above the right eye temporal of every mice group on the first, second, seventh and fourteenth day,observe the retinas’form of organization at the same location, c-fos expression test and do the immunohistochemical analysis under the HE staining. Take the left eye of every mice group to determine the MDA content in the retina tissue, and the T-SOD activity changes. Compare the different groups and do statistical analysis.Results:Of the samples at different times, the first day’s have the most serious damage. These symptoms can be observed under the light microscope:the inner and outer segment boundaries of the light receptor are not clear, the acromere is granular and has hydropic degeneration, the inner segment is disorganized and has a filamentous arrangement and edema. The outer nuclear cells are disorganized, denaturalized and thinned, the white light group is about3to5nucleus thickness, the light damage group, five to six, while the green light group is seven to eight. The samples of the second day show the unclear boundaries between the inner and outer segment have bettered, the acromere is still granular but hydropic degeneration is not so bad as the day before. The inner segment is disorganized and has a filamentous arrangement and edema. The outer nuclear cells are disorganized. The thickness of the green light group is between the white and the light damage groups. The samples of the seventh and the fourteenth day have clear boundaries, the inner segment has filamentous arrangement, the outer nuclear layer is slightly thinner than the normal control, cells are closely arranged, but pyknotic nucleus can still be seen. The white light group is about six to seven nucleus thickness, light damage seven to nine, while green light group is nine to ten. The retinal injury of the green light group is lighter than that of the white light group and the difference has statistical significance (P<0.01). The retinal MDA increases while the SOD decreases in the light damage groups. Compared with the white light group, the green light group has an obvious low content of MDA, and the viability of SOD increased obviously. The difference has statistical significance (P<0.01; P<0.01). Immunohistochemical detection shows that apoptosis after exposure to light occurres mainly in the outer nuclear layer, brown positive staining nuclei appears, and reach maximum in24hours, and then gradually decline, along with lighter colors, the expression quantity of apoptosis-related indicator c-fos of the green reflective group is lower than that of the white reflective group ((P<0.01).Conclusion:Compared with the retinal light damage caused by the white reflected light, the green reflected light’s retinal damage is significantly lower. Green reflected light can lessen retinal light damage, thus play a role in the protection of the eyes.