Experimental retinal dysplasia due to cytosine arabinoside

Retinal dysplasia was produced in newborn rats treated postnatally with the antimitotic substance, cytosine arabinoside (ara-C). In rats examined from 6 to 60 days, there were numerous retinal rosettes surrounded by photoreceptor cells and bipolar cells containing photoreceptor cell processes, displaced nuclei, and cellular debris. Abnormal development and alignment of photoreceptor cell processes were commonly observed. Cellular degeneration was evident at all ages, and infiltrating phagocytic cells were especially numerous in the retina of treated rats examined at 60 days. Characteristic features of ara-C-induced retinal dysplasia included the scattering of bipolar cell nuclei in the inner and outer nuclear layers and marked reduction in the width of the affected retina. Considerable retinal and cerebellar development occurs postnatally in the rat, thus newborn animals might be useful in the testing of possible teratogenic drugs.