RETINAL CHANGES INDUCED BY NEONATAL COCAINE EXPOSURE IN THE RAT

Retinal abnormalities have been described in both animals and humans e xposed to cocaine during development. The present study was designed t o examine the morphological repercussions of neonatal exposure to coca ine on the developing retina of the rat. Male Wistar rats were given 1 5 mg/kg body weight per day of cocaine hydrochloride subcutaneously on postnatal days (PND) 0-6, 13 and 29 and sacrificed at PND 7, 14 or 30 ; controls were given saline. The retinas were processed for electron microscopy. Retina quadrants were embedded flat and vertical semithin and ultra-thin sections obtained. PND 7 sections showed discrete intra retinal hemorrhages, PND 14 sections showed massive intraretinal hemor rhages and images of ischemic necrosis in the nerve fiber layer and PN D 30 sections showed cavity lesions in the hemorrhagic areas, gliosis and pigmented macrophage-rich epiretinal membranes; photoreceptor rose ttes were also found. These results are the first morphological demons tration of retinal hemorrhages and associated epiretinal membranes fol lowing neonatal exposure to cocaine in the rat. These changes are prob ably related to the ischemia/hypoxia induced by cocaine.