DOSE-RESPONSE FUNCTION FOR LENS FORWARD LIGHT-SCATTERING AFTER IN-VIVO EXPOSURE TO ULTRAVIOLET-RADIATION

Background: It is known that different types of radiation, as well as aging and metabolic disorders, can cause cataract. Several epidemiolog ical investigations show a correlation between cataract development an d the dose of ultraviolet radiation (UVR) received. It is well establi shed experimentally that exposure of animal eyes to UVR induces catara ct. The purpose of the present study was to determine the dose-respons e function for UVR-induced opacities in the rat lens after in vivo exp osure. Methods: Sprague-Dawley rats received 0.1, 0.4, 1.3, 3, 5, 8 or 14 kJ/m(2) UVR (lambda(MAX)=300 nm, lambda(0.5)=10 nm) unilaterally f or 15 min. At 1 week after exposure both lenses were removed, photogra phs were taken and the intensity of forward-scattered light was measur ed. Results: One week after WR exposure, opacities occurred on the len s surface, as observed with a microscope. With increased UVR dose the opacities became more intense and occurred also in the equatorial area of the lens, but not in the nucleus. The intensity of forward light s cattering increased with increased UVR dose between 3 and 14 kJ/m(2). No significant change in intensity of forward light scattering was obs erved for lower UVR doses. Conclusion: The intensity of forward light scattering in the rat lens increases exponentially with increased WR d ose between 0.1 and 14 kJ/m(2).