A rabbit model of proliferative vitreoretinopathy induced by injection of astrocytic cultures

1. The objective of this study was to decipher whether proliferation of ast rocytes and invasion of astrocytic processes into the retina could contribu te to retinal detachment ill a rabbit model. 2. Cultures of astrocytes were injected intravitreally into the eyes of alb ino rabbits. 3. Two weeks after injection, proliferation of astrocytes on the retinal su rfaces was observed. Vascular endothelial growth factor (VEGF) and prolifer ative cell nuclear antigen (PCNA) were found by immunohistochemistry to be expressed in the center of the astrocytic growth. 4. Using the same immunohistochemical technique to visualize glial fibrilla ry acidic protein (GFAP), a marker for astrocytes, processes of astrocytes in the growth were observed to penetrate into the host retina. 5. Retinal detachment was then confirmed by ultrasound, histologically, and grossly 2 weeks after injection of astrocytes. 6. Histochemistry on esterase indicated chloroesterase positive cells insid e the growth. The secretion of this form of esterase might soften the vitre ous and enhanced retinal detachment. 7. Six weeks after injection, VEGF and PCNA decreased in the astrocytic gro wth but astrocytic processes still attached onto and penetrated the host re tina. 8. This study suggests that astrocytes could be a major factor in inducing retinal detachment.