Effects of prenatal cocaine exposure in the photoreceptor cells of the rat retina.

Despite the increasing evidence of eye abnormalities, the effects of prenatal exposure to cocaine on the visual system are still poorly understood. This study was aimed at analyzing the qualitative and quantitative organization of the retinal photoreceptor cells (PR) and outer nuclear layer (ONL) after prenatal exposure to cocaine in the rat. Pregnant Wistar rats were given sc injections of cocaine hydrochloride (60 mg/kg body wt/d) or saline or were not manipulated; analyses were performed in the 14- and 30-d-old male offspring. Radial semithin and ultrathin sections of epon-embedded flat mounts of the retina showed displaced PR-like cells in the inner nuclear layer (INL), picnotic PR nuclei in INL, and ONL, and retinal PR rosettes and outer-segment debris in the subretinal space. The quantitative study showed an increased density of PR-like nuclei in the INL in PND14 cocaine-treated rats that were within normal values at PND30; no changes were detected in the PR mean nuclear diameter and in the packing density of PR nuclei in the ONL. These data constitute the first morphological demonstration of photoreceptor damage after prenatal cocaine-exposure probably owing to a direct action of the drug and/or to the cocaine-induced ischemia/hypoxia.

Effects of prenatal cocaine exposure in the retinal ganglion cell layer of the rat. A morphometric analysis.

To study the effects of prenatal cocaine-exposure on the developing retinal ganglion cell layer of the rat, female Wistar rats were administered subcutaneously (sc) cocaine hydrochloride (60 mg/kg body wt/d) or saline, or were not manipulated from gestational d 8-22. Male offspring were sacrificed at postnatal day 14 and 30. Radial semithin sections of epon-embedded flat mounts of the retinal quadrants were used to evaluate the following parameters along the centroperipheral axis: 1. Thickness of ganglion cells plus nerve fiber layer; 2. Nuclear size of ganglion cell layer neurons; and 3. Linear density (number per unit length) of ganglion cell layer neurons. To study the effects of cocaine and age on the retinal areas (temporal/nasal, dorsal/ventral), a repeated measures analysis of variance was used for each of the parameters mentioned above. All parameters were affected by prenatal exposure to cocaine. The thickness of the ganglion cell plus nerve fiber layer was reduced in cocaine-exposed rats in comparison with the saline group. Nuclear diameters were smaller in the cocaine than in the saline and control groups. The linear density was higher in the cocaine-exposed group than in the control and saline groups. The age-dependent decrease in the linear density from postnatal day 14-30 was higher in the cocaine-exposed rats than in the saline group; the decrease in the linear density along the centroperipheral axis found in both the control and saline groups was not significant in the cocaine-treated group. These morphometric findings strongly support the view that prenatal cocaine-exposure induces marked changes in the organization of the developing retina.

Morphological and biochemical assessment of the cornea in a Gaucher disease carrier with keratoconus.

Ocular abnormalities such as corneal opacities and some specific alterations in ocular movements have been described in the neuropathic forms of Gaucher disease. This study was designed to correlate the clinical, morphological and biochemical findings in the corneal button obtained after keratoplasty in a Gaucher disease carrier with keratoconus. Morphologically, the cornea showed keratocytes with marked dilatations of the rough endoplasmic reticulum and intracytoplasmic "dark inclusions"; the acidic lipid profiles presented alterations in the cornea of the Gaucher disease carrier when compared with healthy controls and a clear deficiency in beta-glucosidase activity was detected as well. Our data suggest that the cornea may serve as a good marker of an early target organ in lipid metabolism disorders such as Gaucher's disease.

Retinal changes induced by neonatal cocaine exposure in the rat.

Retinal abnormalities have been described in both animals and humans exposed to cocaine during development. The present study was designed to examine the morphological repercussions of neonatal exposure to cocaine on the developing retina of the rat. Male Wistar rats were given 15 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. Retinal quadrants were embedded flat and vertical semithin and ultrathin sections obtained. PND 7 sections showed discrete intraretinal hemorrhages, PND 14 sections showed massive intraretinal hemorrhages and images of ischemic necrosis in the nerve fiber layer and PND 30 sections showed cavity lesions in the hemorrhagic areas, gliosis and pigmented macrophage-rich epiretinal membranes; photoreceptor rosettes were also found. These results are the first morphological demonstration of retinal hemorrhages and associated epiretinal membranes following neonatal exposure to cocaine in the rat. These changes are probably related to the ischemia/hypoxia induced by cocaine.