Lifetime Study in mice: 24 months follow up after low doses of ionizing radiation with Scheimpflug imaging and OCT

Abstract

SummaryAt the adult age of 10 weeks male and female hybrid mice (C57BL/6 × C3H F1) were acutely whole‐body irradiated with low doses of ionising radiation (0, 0.063, 0.125 and 0.5 Gy) using a 60Co source. Over the following 24 months the mice were examined monthly for lens opacities by Scheimpflug imaging and every four months for retinal effects by OCT (optical coherence tomography). To estimate the contribution of genetic effects, virtually healthy mice heterozygous for an Ercc2 mutation were compared to wild‐type mice of the same strain background.Additional groups of mice were sacrificed at various time points (4 and 24 h, 12, 18 and 24 months after irradiation) to investigate the underlying mechanisms of radiation‐induced effects on the eye and other organs. Histological and immunohistochemical analysis of the eyes are done.Even at the highest dose of 0.5 Gy, analysis of the Scheimpflug examinations in irradiated wild‐type mice did not show significant differences in lens opacity compared to the unirradiated control group or the heterozygous mutants up to 24 months after irradiation. OCT data showed a reduction of the retinal thickness in irradiated heterozygous mutants, but not in wild‐type mice.