Aluminum Chloride Induces Retinal Changes in the Rat

We studied rat retinal changes due to aluminum (Al) toxicosis with a transmission electron microscope (TEM) and an energy dispersive X-ray analyzer (EDXA). Normal 4-week-old Wistar Kyoto rats were divided randomly into Al toxicosis and control groups. The Al toxicosis group was injected ip with 0.3 ml of 4% aluminum chloride (AlCl3) per day every day for 16 weeks. The retina was examined with a TEM and EDXA at 8, 12, and 16 weeks after starting injections with AlCl3. There was a statistically significant increase in the serum Al concentration in the Al toxicosis group (p < 0.001). We observed prominent pathologic changes at 16 weeks after the first injections. Thin retinal pigment epithelium (RPE), and disappearance of the photoreceptor outer and inner segments and nuclei were observed. There were high-density irregular granules in the outer and inner plexiform layers and in the inner nuclear layer. We found dense granules in the cells, which remained between the RPE and the inner nuclear layer. EDXA detected Al in the high-density irregular granules in these areas. Al injected ip caused accumulation of Al in the rat retina and the destruction of photoreceptor cells. These findings indicate that Al is toxic to the retina.