Ofloxacin-associated retinopathy in rabbits: role of oxidative stress

Ofloxacin, a quinolone, is an extensively used, well-tolerated antibacterial agent but has been reported to induce photosensitivity at low incidences. In the present investigation, the possible role of oxidative stress in ofloxacin-induced retinopathy in rabbits was evaluated. It was observed that ofloxacin at a dose rate of 10 and 20mg/rabbit, twice daily for 21 consecutive days, resulted in significant elevation in the extent of lipid peroxidation and depletion of the blood glutathione levels. Marked alterations were also observed in various parameters of the glutathione-redox cycle. There was significant increase in the enzymic activity of glutathione peroxidase and glutathione reductase, whereas a significant decrease was observed in the activities of superoxide dismutase, catalase, and glutathione-S-transferase enzymes. Histopathological studies revealed retinal damage especially in the pigmented cell layer. Degenerative changes in liver and kidneys were also observed. Liver showed focal areas of necrosis, dilation of sinusoids, and cellular infiltration, whereas in kidneys, there was glomerular and tubular degeneration, suggesting impaired renal functioning.