眼部生物光谱有效紫外线暴露定量及其与眼损伤的量效关系研究

To illustrate the levels and diurnal variations of solar biological effective ultraviolet radiation (UV) exposure on the eye（cornea and lens），specially designed optical fibers will be placed in rabbit eyes which is fixed at the rotating manikin we had used before. With this new improved manikin,we will monitor the ocular UV exposure at Sanya and Lasa,China(which are extremal UV region).Based on the measured ocular spectral irradiance at wavelength in these two region,the biological effective UV exposure on the eye for photokeratitis and cataract was calculated by the spectral irradiance weighted by the action spectra. And then the diurnal variations will be clarified, and the high-risk solar elevation angle,high-risk orientation angle and high-risk time period in a day will be illustrated. Additonally, based on the biological effective UV exposure,the animal UV irradiate experiment on the rabbit eye and cell UV irradiate experiment on the corneal and lens epithelial cells of human eye will be conducted. Therefore，we could determine the dose-effect relationship between eye injury and biological effective UV exposure under the solar UV environment, compare the results with previously experimental studies which were based on the environmental physical UV exposure, and analyze the impacts of the UV exposure level （biological effective UV exposure and environmental physical UV exposure）to the cell apoptosis,oxidative damage and DNA damage. These information will be important for the research on the assessment of the risk of ocular solar UV exposure and will provide new scientific evidence for the ocular UV exposure levels division in experimental research on the mechanism of UV injury.

为了揭示眼部生物组织（角膜和晶体）中实际接受光谱有效紫外线暴露水平和规律，本研究将置入特制光纤的兔眼固定在原有旋转式眼紫外线暴露模型中，在我国三亚和拉萨两个紫外线极值地区进行眼部生物组织日光紫外光谱辐射的监测。通过获取实际作用于角膜和晶体的紫外光谱物理强度，经紫外线致眼角膜和晶体损伤作用光谱加权定量眼部生物光谱有效紫外线暴露强度，从而阐明眼部紫外线暴露的日间分布规律、高危太阳高度角、高危朝向角和日间高危时间段。我们以眼部生物光谱有效紫外线暴露强度为依据，进行紫外线照射的兔眼动物实验和正常人眼组织细胞实验，确定不同眼部生物光谱有效紫外线暴露水平与眼损伤的量效关系，并与以往以环境紫外线暴露为依据的实验研究结果相比较，分析两者因暴露水平上的差异对细胞凋亡、氧化损伤和DNA损伤量效关系研究的影响，为眼部紫外线暴露危险性的准确评价和眼紫外线损伤机制实验研究的暴露剂量划分提供新的科学依据。

为了揭示眼部生物组织（角膜和晶体）中实际接受光谱有效紫外线暴露水平和规律，本研究将置入探头的猪眼球固定在原有旋转式眼紫外线暴露模型中，在我国三亚地区进行眼部生物组织日光紫外光谱辐射的监测。获取了实际作用于角膜和晶体的紫外光谱物理暴露吸收强度，阐明了眼部紫外线暴露的日间分布规律、高危太阳高度角和日间高危时间段，并且，经本研究发现紫外线生物组织吸收角膜在日间上下午时段的吸收率更高，约达80%，正午吸收率却相对较低，且UVB的吸收率高于UVA。我们以眼部生物光谱有效紫外线暴露强度为依据，进行紫外线照射的人晶状体上皮细胞实验，确定不同眼部生物光谱有效紫外线暴露水平与眼损伤的量效关系，发现随着紫外暴露强度的增加，细胞发生更严重的病理改变，MDA水平升高。除500μW/cm2暴露组外，其他暴露组随着紫外辐照强度的增大，凋亡率逐渐升高；T-SOD活力，CAT活力逐渐升高；T-AOC，GSH-PX水平逐渐下降。本研究分析因暴露水平上的差异对细胞凋亡、氧化损伤量效关系的影响，为眼部紫外线暴露危险性的准确评价和眼紫外线损伤机制实验研究的暴露剂量划分提供新的科学依据。