Retinal blood vessels are damaged in a rat model of NMDA-induced retinal degeneration.

Retinal ischemia-reperfusion causes capillary degeneration but the mechanisms of damage are not well understood. The NMDA receptor plays an important role in neuronal damage after ischemia-reperfusion. Therefore, we determined whether retinal blood vessels are damaged structurally and functionally in a rat model of retinal degeneration induced by NMDA. At 7 days after a single intravitreal injection of NMDA (200nmol) into the eye, loss of retinal ganglion cells and thinning of the inner plexiform layer were observed. Endothelial cells disappeared in some regressing vessels and empty basement membrane sleeves were left as remnants of the vessels. The number of basement membrane sleeves was increased in the NMDA-treated retina and non-perfused vessels were found in the injured retina. These results indicate that retinal blood vessels are damaged in the NMDA-induced retinal degeneration model. Neuronal cells may play a role in maintaining normal structure and function of the vasculature in the retina.