Platelet-derived growth factor plays a key role in proliferative vitreoretinopathy

PURPOSE. The action of growth factors is thought to make a substantial cont ribution to the events leading to proliferative vitreoretinopathy (PVR). In this study, the importance of platelet-derived growth factor (PDGF) was te sted in a rabbit model of PVR. METHODS. The approach was to compare the extent of PVR induced by cells tha t do or do not express the receptors for PDGF and therefore differ in their ability to respond to PDGF. RESULTS. Mouse embryo fibroblasts derived from PDGF receptor knock-out embr yos that do not express either of the two PDGF receptors induced PVR poorly when injected into the eyes of rabbits that had previously undergone gas v itrectomy. Re-expression of the PDGF beta receptor in these cells did not i mprove the ability of the cells to cause PVR. In Contrast, injection of cel ls expressing the PDGF a receptor resulted in stage 3 or higher PVR in 8 of 10 animals. CONCLUSIONS. These findings show that PDGF makes an important contribution to the development of PVR in this animal model. Furthermore, there is a mar ked difference between the two receptors for PDGF, and it is the PDGF cu re ceptor that is capable of driving events that lead to PVR.