A Rabbit Model of Proliferative Vitreoretinopathy Induced by Injection of Astrocytic Cultures

1.The objective of this study was to decipher whether proliferation of astrocytes and invasion of astrocytic processes into the retina could contribute to retinal detachment in a rabbit model.2.Cultures of astrocytes were injected intravitreally into the eyes of albino rabbits.3.Two weeks after injection, proliferation of astrocytes on the retinal surfaces was observed. Vascular endothelial growth factor (VEGF) and proliferative 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 fibrillary 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 inside the growth. The secretion of this form of esterase might soften the vitreous and enhanced retinal detachment.7.Six weeks after injection, VEGF and PCNA decreased in the astrocytic growth but astrocytic processes still attached onto and penetrated the host retina.8.This study suggests that astrocytes could be a major factor in inducing retinal detachment.