Glucocorticoids have great clinical importance as anti-inflammatory drugs. Dexamethasone, a long acting synthetic steroid, was used in the present study to investigate its effect chronically and acutely on the retina of adult pregnant mice and their newborns. Pregnant mice were divided into three control groups and three experimental ones. The pregnant mice of the first experimental group were treated by a daily subcutaneous therapeutic dose of 0.02 mg dexamethasone from the 1st to the 21st day of gestation (chronic). The pregnant mice of the second experimental group were given the same dose of dexamethasone from the 7th day to the 14th day of gestation (acute), while the pregnant mice of the third group were given the same dose of the drug from the 14th day to the 21st day of gestation (acute). At the end of treatment, the retina of the adults of the first group, retina of the adults and newly born mice of the second and third groups were dissected and prepared for microscopical examination. The thickness of the whole retinal layers has decreased in the adult following dexamethasone administration and was time dependent, while the retinal tissue of the newly born mice showed an increase in thickness. Electron microscopic examination of adult and newborns revealed vacuolation of the pigmented epithelial cells. In the adults, the outer segments of the photoreceptors revealed extensive disorganization and degeneration. Degenerated cytoplasmic areas in the outer nuclear layer cells were seen. Moreover, swollen and vacuolated mitochondria were also observed in the cytoplasm of the inner nuclear layer cells. Nuclear membrane detachment was detected in the outer nuclear layer of the newborns. However, the ganglionic cells in the adult and newborn retinas were intact. In conclusion, this study revealed that prolonged administration of dexamethasone, obviously affects the retinal tissue of both pregnant and newly born mice and visual dysfunction may be expected
Key words: Dexamethasone, Retina, Pregnant Mice, Newly Born
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