A light and electron microscopy observation of diabetic retinopathy in rats

Objective:To observe the pathologic changes of the retinal ganglion cells(RGCs)and capillary in rats with diabetes mellitus for seven months.Methods:Diabetic rats were induced by streptozotocin.After seven months we removed the eyes under anesthesia and made retinal slides and digest preparations.The RGCs and capillary were observed by light and electron microscopy.Results:In light microscopy the retinal tissues were indistinct disturbance and capillaries were enlarged.There were some early symptoms of diabetic retinopathy(DR),such as extensive pericyte loss,endothelial cell proliferation,pericyte ghost,acellular capillary and apoptosis of endothelial cell.Retinal nerve fiber layer was edematous,nuclear shrinkage and mitochondrion condensed.In electron microscopy endothelial cell of capillary and mitochondrial was edematous obviously,the basement membranes were thickened.RGCs were vacuolated,chromatin of nucleus aggregated marginally decreased and densification.Some of RGCs were necrosis,nucleus were dissolved,mitochondria was edematous,the rough endoplasmic reticula decreased obviously.Conclusion:In the early stage of DR in rats,accompanying the retinal capillary,the RGCs were damaged.