Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Jun 1998
Light history and age-related changes in retinal light damage.
To determine the effects of age and long-term light- or dark-rearing environments on acute, intense-light-mediated retinal degeneration. ⋯ The age-related increase in susceptibility to retinal light damage in rats is influenced by their long-term daily light history. Decreasing retinal irradiance by dark-rearing eliminates the age-related increase in light damage, suggesting a correlation between light environment and retinal gene expression associated with damage. In all rats, retinal light damage resulted in a pattern of DNA fragmentation consistent with apoptotic cell death and in an increased expression of HO-1 mRNA. Antioxidant treatment greatly reduced apoptosis and HO-1 expression. This indicates that light damage involves an oxidative process that may also trigger apoptosis in the retina. The rat aging model may provide useful insights into the role of light environment associated with retinal degeneration in an aging human population.