Retinal lesions in rat fetuses prenatally exposed to cocaine

The increased use of cocaine in the United States and worldwide has created great concern about its effects on fetuses and neonates of pregnant cocaine abusers. The effects on neonates are varied: fetal growth delay, microcephaly, abnormal neurological functions, microphthalmia, and maternal obstetric complications. In this study, the effect of prenatal cocaine administration was studied microscopically in the retina of rat fetuses. Twenty-five pregnant Wistar rats were injected i.p. with an aqueous cocaine solution using a 30 mg/kg daily dose for 45 days. Control group rats (15 pregnant animals) received saline solution for the same period. Day 0 of gestation was the day after mating. Dosing began on this day. The rats were killed on gestation day 21 and fetuses were obtained for examination. The histopathological light and electron microscope studies of the retinas showed interstitial oedema, areas depleted of cells, necrosis, and hyperchromatic ganglion cells. There also was a significantly lower number of retinal cells compared to control fetuses. In four cases, teratogenic lesions of the retina were observed whereas no changes were present in control fetuses. Results indicate that development of retina in fetuses prenatally exposed to cocaine was altered by cocaine exposure.