CONICET | Buscador de Institutos y Recursos Humanos

Diabetic retinopathy (DR) is a leading cause of acquired blindness. Visual function disorders have been demonstrated in diabetics with very early retinopathy or even before the onset of retinopathy. Although DR has long been recognized as a vascular disease, it is becoming increasingly clear that retinal ganglion cells (RGC) are also affected by diabetes. The aim of the present work was to analyze the visual pathway in an early step of experimental diabetes. Diabetes was induced in Wistar rats by an injection of streptozotocin (STZ). At different times after diabetes-induction, the visual pathway was morphometrically evaluated. A deficit in the anterograde transport from the retina to the superior colliculus at 6 weeks post STZ-injection was observed. At this time point, no RGC loss or substantial alterations in the superior colliculus were found. A large increase in astrocytes reactivity occurred in the distal portion of the optic nerve, which coincided with a significant axon loss. Moreover, profound myelin alterations and altered morphology of oligodendrocyte lineage were observed. The present results suggest that axoglial alterations at the distal portion of the optic nerve could be the first structural change in the diabetic visual pathway.