Development of electroretinographic alterations in streptozotocin-induced diabetes in rats

Development of electroretinographic alterations in 9-week-old experimental diabetic rats was studied for up to 6 weeks after a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). The amplitudes and the peak latencies of the a and b waves in the diabetic rats did not differ significantly from those in the control rats. In contrast, the diabetic rats showed a significantly smaller amplitude of the second oscillatory potential (OP) 6 weeks after STZ treatment, and furthermore significantly delayed OP peaks as early as 2-3 weeks after STZ treatment. Vitreous fluorophotometric abnormality developed 6 weeks after STZ treatment. None of the diabetic rats had fundus angiographic changes. These results suggest that hyperglycemia or its related changes rapidly affects the light-induced electrical activities of the retina.