Unbalanced vitreous levels of pigment epithelium-derived factor and vascular endothelial growth factor in diabetic retinopathy

Abstract

PURPOSE: To determine the levels of pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) in the vitreous of patients with diabetic retinopathy (DR). DESIGN: Experimental study of PEDF and VEGF levels in vitreous samples collected during vitrectomy. METHODS: The levels of PEDF and VEGF were measured by enzyme-linked immunosorbent assay in the vitreous of 46 eyes of 43 patients who underwent vitrectomy with diabetic retinopathy (DR) (32 eyes of 29 patients) and an idiopathic macular hole (MH) (14 eyes of 14 patients). RESULTS: The vitreal concentration of PEDF was significantly lower at 1.11 ± 0.14 μg/ml (mean ± standard error) in eyes with DR than in eyes with MH at 1.71 ± 0.22 μg/ml ( P = .021). The VEGF level was 1799 ± 478 pg/ml in eyes with DR and not detectable in MH. The PEDF level in proliferative DR (PDR) (0.94 ± 0.12 μg/ml) was lower than that in nonproliferative DR (NPDR) (2.25 ± 0.32 μg/ml), and that in active DR (0.85 ± 0.14 μg/ml) was significantly lower than that in inactive DR (1.59 ± 0.24 μg/ml; P = .01). The VEGF level was 2025 ± 533 pg/ml in PDR and 215 ± 201 pg/ml in NPDR and that in active DR (2543 ± 673 pg/ml) was significantly higher than that in inactive DR (395 ± 188 pg/ml; P = .0098). CONCLUSIONS: These results suggest that lower levels of PEDF and higher levels of VEGF may be related to the angiogenesis in DR that leads to active PDR.