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 epidemiological investigations show a correlation between cataract development and the dose of ultraviolet radiation (UVR) received. It is well established experimentally that exposure of animal eyes to UVR induces cataract. The purpose of the present study was to determine the dose-response function for UVR-induced opacities in the rat lens after in vivo exposure. · Methods: Sprague-Dawley rats received 0.1, 0.4, 1.3, 3, 5, 8 or 14 kJ/m² UVR (λ_MAX=300 nm, λ_0.5=10 nm) unilaterally for 15 min. At 1 week after exposure both lenses were removed, photographs were taken and the intensity of forward-scattered light was measured. · Results: One week after UVR exposure, opacities occurred on the lens 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 scattering increased with increased UVR dose between 3 and 14 kJ/m². No significant change in intensity of forward light scattering was observed for lower UVR doses. · Conclusion: The intensity of forward light scattering in the rat lens increases exponentially with increased UVR dose between 0.1 and 14 kJ/m². [ABSTRACT FROM AUTHOR]