Electron Microscopic Observations on Paravascular Retinal Rarefaction and Acellular Capillaries in a Senile Human Eye

Abstract

In a senile human eye, formation of a large perivascular space around peripheral retinal capillaries was observed, followed by densification, rarefaction and finally total necrosis of the paravascular glial tissue. In the latest stages of glial necrosis, a direct connection between the vitreous cortex and the perivascular space may result. The findings suggest that paravascular rarefaction is caused rather by vascular disturbance (‘capillarosclerosis’) than by vitreous traction. Paravascular retinal rarefaction with total necrosis of the glial tissue may also occur adjacent to acellular capillaries. The following fine structural changes in acellular capillaries are described: total or almost total loss of cellularity, infiltration of Müller cells through the residual basement membrane sheets, formation of fine collagen fibrils within the capillary lumen.