Further studies on the effects of UV radiation on the human lens

Young (1st decade) and old (7th decade) normal human lenses were exposed to low-level (less than 1 mW/cm2) broadband UV radiation (300-400 nm). UV-induced effects in the whole lens and the extracted lens proteins were monitored by fluorescence spectroscopy. The lens proteins were also subjected to proton and pulse magnetization NMR spectroscopy. These studies provide further evidence that low-level UV radiation exposure enhances nontryptophan fluorescence and may generate additional (longer wavelength) chromophores. The NMR studies suggest that the young gamma crystallin fraction is particularly sensitive to UV radiation compared with the other crystallins.