PURPOSE. Transforming growth factor (TGF)- β 2 and hepatocyte growth factor (HGF) have been implicated in the pathogenesis of proliferative vitreoretinopathy (PVR) after retinal detachment surgery. The exact role of these factors in the early events, immediately after primary retinal detachment, is not yet known, and determining their roles was therefore the purpose of this study. METHODS. Subretinal fluids were collected prospectively from 144 patients during surgery for scleral buckling. TGF- β 2and HGF were measured with commercially available ELISA kits. Thirty patients in whom a redetachment caused by postoperative PVR developed, were compared with 114 patients with an uncomplicated retinal detachment. The controls included 18 vitreous samples from patients with macular hole or pucker. Multivariate regression analysis was used to compare the relative roles of growth factors and clinical factors in the development of PVR. RESULTS. The median amount of subretinal TGF- β 2 was approximately two times lower in patients with postoperative PVR (1.9 ng/mL) than in the uncomplicated detachment group (3.3 ng/mL; P=0.002). TGF- β 2 levels in the PVR- positive group were similar to control vitreous levels (1.8 ng/mL). Subretinal HGF concentrations were not significantly different between the two groups of patients (PVR positive: 8.8 ng/mL; PVR negative: 8.9 ng/mL), but were higher than control vitreous levels (4.6 ng/mL; P=0.01). Stepwise multivariate logistic regression analysis revealed that of all factors under study, decreased TGF- β 2 content was the exclusive predictor of postoperative PVR (P=0.01). CON- CLUSIONS. High TGF- β 2 levels in subretinal fluid at the time of primary retinal detachment may protect a patient against subsequent development of PVR. PURPOSE. Transforming growth factor (TGF) - β 2 and hepatocyte growth factor (HGF) have been implicated in the pathogenesis of proliferative vitreoretinopathy (PVR) after retinal detachment surgery. The exact role of these factors in the early events, immediately after primary retinal detachment, is not yet known, and determined that roles was therefore the purpose of this study. METHODS. Subretinal fluids were collected prospectively from 144 patients during surgery for scleral buckling. TGF-β 2 and HGF were measured with commercially available ELISA kits. Thirty patients in whom a redetachment caused by postoperative PVR developed, were compared with 114 patients with an uncomplicated retinal detachment. The controls included 18 vitreous samples from patients with macular hole or pucker. Multivariate regression analysis was used to compare the relative roles of growth factors and clinical factors in the development of PVR. RESULTS. The median amount of subretinal TGF-β 2 was app Two times lower in patients with postoperative PVR (1.9 ng / mL) than in the uncomplicated detachment group (3.3 ng / mL; P = 0.002). TGF- β 2 levels in the PVR- positive group were similar to control vitreous levels ( 1.8 ng / mL). Subretinal HGF concentrations were not significantly different between the two groups of patients (PVR positive: 8.8 ng / mL; PVR negative: 8.9 ng / mL) P = 0.01). Stepwise multivariate logistic regression analysis revealed that of all factors under study, decreased TGF-β 2 content was the exclusive predictor of postoperative PVR (P = 0.01). CON- CLUSIONS. High TGF- β 2 levels in subretinal fluid at the time of primary retinal detachment may protect a patient against subsequent development of PVR.