ERG ANALYSIS REVEALS REDUCED FUNCTION IN ON-CENTER BIPOLAR CELLS OF GLUCOSE-TREATED ZEBRAFISH

Retinopathy is established as a consequence of diabetes mellitus in humans and has proven to lead to irreversible visual loss, often ending in blindness. Alterations in biochemical interactions in the retina due to chronic hyperglycemia can damage retinal vasculature leading to varying degrees of visual loss in diabetic individuals. This study proposes to further establish Danio rerio as an animal model for diabetic retinopathy. After inducing hyperglycemia in zebrafish through alternation between glucose-treated and normal water, retinal physiology was studied using ERGs to identify functional changes in the retinal tissues. Results revealed retinas exposed to hyperglycemia for 30 days had reduced b-wave activity in ERGs when compared to osmotic and water controls indicating reduced ON-center bipolar cell functionality. Reduced b-wave amplitudes were observed at peak absorption wavelengths for all four cone types. Reduced functionality in zebrafish retinas after hyperglycemia exposure supports their establishment as an animal model for diabetic retinopathy.