Abstract
Abstract: :
Purpose:Pigment epithelium-derived factor (PEDF) is a protein shown to have neuroprotective activity. PEDF has been also reported to be a potent inhibitor of ocular angiogenesis. The aim of this study was to determine the levels of PEDF and vascular endothelial growth factor (VEGF) in the vitreous of patients with diabetic retinopathy (DR) and also to determine whether panretinal photocoagulation (PRP) affects the vitreous levels of PEDF and VEGF. Methods: The levels of PEDF and VEGF were measured by enzyme-linked immunosorbent assay (ELISA) in the vitreous of 51 eyes of 48 patients who underwent vitrectomy with diabetic retinopathy (DR) (36 eyes of 33 patients) and an idiopathic macular hole (MH) (15 eyes of 15 patients). Results:The vitreal concentration of PEDF was significantly lower at 1.00 ± 0.13 µg/ml (mean± standard error) in eyes with DR than in eyes with MH at 1.62 ± 0.23 µg/ml (P =0.021). The VEGF level was 1688 ± 429 pg/ml in eyes with DR and not detectable in MH. The PEDF level in proliferative diabetic retinopathy (PDR) (0.84 ± 0.12 µg/ml) was lower than that in nonproliferative diabetic retinopathy (NPDR) (2.25 ± 0.32 µg/ml), and that in active DR (0.76 ± 0.13 µg/ml) was significantly lower than that in quiescent DR (1.48 ± 0.25 µg/ml; P =0.01). The VEGF level was 1871 ± 472 pg/ml in PDR and 215 ± 201 pg/ml in NPDR, and that in active DR (2341 ±597 pg/ml) was significantly higher than that in quiescent DR (376 ± 172 pg/ml; P = 0.0098). We found lower levels of VEGF in eyes following PRP treatment, however there was no correlation between the PEDF levels and PRP treatment. Conclusions:These results suggest that lower levels of PEDF and higher levels of VEGF may be related to the angiogenesis in diabetic retinopathy that leads to active PDR.
Keywords: diabetic retinopathy • growth factors/growth factor receptors • neovascularization