Ultraviolet radiation and cataract
Ultraviolet radiation and cataract
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DOI：
10.1089/jop.2000.16.285
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发表时间：
2000-06-01
影响因子：
2.3
通讯作者：
Balasubramanian, D
中科院分区：
文献类型：
--
作者：
Balasubramanian, D
虽然落在地球上的太阳辐射包括红外线、可见光、UVA、UVB、甚至UVC范围内的光，但是入射在眼睛透镜上并且因此对眼睛透镜的生物学很重要的光基本上在可见光和UVA范围内。因此，UVB辐射对透镜的直接光化学损伤很小，尽管长期UVA（甚至可见光范围）照射会导致透镜故障。透镜在体内短期暴露于UVA光导致受损的光学和生物化学性质，这些性质被及时修复，而较高剂量则会造成永久性损伤。透镜中的这种较长波长的光介导的变化通过光动力学方式发生，受到在一段时间内在透镜中积累的一些化合物的影响，这些化合物充当敏化剂。已经分离和鉴定了十几种这样的化合物，并研究了它们的光活性。虽然其中几种是光动力的，当UVA光照射在它们上时会产生活性氧，但在透镜中积累的其他化合物起着抗氧化剂的作用。
While solar radiation falling on earth comprises light in the infrared, visible, UVA, UVB, and even UVC ranges, the light incident on, and thus important to the biology of, the eye lens is essentially in the visible and UVA regions. Thus, direct photochemical damage to the lens from UVB radiation is minor, though long-term UVA (and even visible range) irradiation is seen to lead to lens malfunction. Short-term exposure of the lens in vivo to UVA light leads to compromised optical and biochemical properties which are repaired in time, while higher doses affect permanent damage. Such longer wavelength light-mediated changes in the lens occur through photodynamic means, affected by some of the compounds that accumulate in the lens over a period of time, which act as sensitizers. Isolation and chemical identification of over a dozen such compounds has been done, and their photoactive properties have been studied. While several of these are photodynamic and generate reactive oxygen species when UVA light is shone on them, other compounds that accumulate in the lens act as antioxidants.