RETINAL HEMORRHAGES ASSOCIATED WITH IN-UTERO EXPOSURE TO COCAINE - EXPERIMENTAL AND CLINICAL FINDINGS

Background: The use of drugs of abuse-e.g., cocaine-during pregnancy h as been associated with abnormalities of the visual system, The author s studied the effects of prenatal exposure to drugs of abuse, especial ly cocaine, on the vascular system of the retina in newborn infants an d in an experimental model in the rat. Methods: The animal study was c onducted in pregnant Wistar rats injected subcutaneously with cocaine hydrochloride (60 mg/kg body weight/day) from gestation days 8 to 22. Male offspring were killed at postnatal days 7, 14, and 30 and perfuse d with fixative, and the retinas were dissected and processed for micr oscopic observation. The ophthalmologic observations were conducted in a population of newborn infants born to women who abused many drugs d uring pregnancy and in a control group of women with no history of ill icit drug use. Results: Vascular disruptive lesions were seen after pr enatal exposure to cocaine in the rat: round intraretinal hemorrhages, ischemic and hypoperfused areas located at the temporal part and ofte n extending from the posterior pole to the periphery of the retina. Th e ophthalmologic observation of the newborns showed a higher incidence of vascular disruptive lesions in infants in whom exposure to drugs o f abuse was affirmative during pregnancy. In the cases in which cocain e consumption was reported, they consisted in blot full-thickness hemo rrhages with rounded domed contours suggestive of venous occlusion and retinal ischemia, very similar to the lesions seen in the animal mode l. These hemorrhagic lesions, morphologically similar to neonatal reti nal hemorrhages, had a higher incidence than in controls; they also to ok longer to resolve when compared with the reabsorption time of the n eonatal hemorrhages due to birth trauma and the hemorrhagic lesions in newborns of mothers in whom consumption of other drugs-but not cocain e-were reported. Conclusion: A topographic and morphologic parallelism can be established between the retinal vascular alterations found in humans consuming cocaine and in the animal model of prenatal exposure to this drug of abuse; although findings from animal studies may be di fficult to apply directly to humans, these data strongly support that cocaine can be a causal factor for the occurrence of retinal vascular disruption in newborns.