Cellular proliferation induced by subretinal injection of vitreous in the rabbit

A new experimental model of subretinal cellular proliferation, based on injection of autologous vitreous into the subretinal space of rabbits, was studied by light and electron microscopy. As early as five days after injection, proliferation of retinal pigment epithelial (RPE) and retinal glial cells was observed in the subretinal space. These morphologically distinct proliferating cells were sometimes joined by junctional complexes. Morphologically, the proliferating RPE cells resembled either RPE cells or fibroblasts. Some proliferating RPE cells also retained their epithelial characteristics (ie, basement membranes and cell junctions), while others were partially dedifferentiated and showed some embryonic features. New formation of melanin could be identified within the proliferated RPE cells, which could account, in part, for the hyperpigmentation at the site of the bleb caused by the injection of vitreous. The results demonstrated that injection of autologous vitreous into the subretinal space can lead to subretinal proliferation of retinal glial and RPE cells in the rabbit.