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Aim: To investigate the pooled prevalence of diabetic retinopathy (DR), proliferative DR (PDR) and nonproliferative DR (NPDR) in Asian type 2 diabetes mellitus (T2DM) patients., Methods: We performed a systematic search online search using PubMed, EMBASE, Web of Science, the Cochrane Library, and China WeiPu Library to identify eligible studies that reported the prevalence of DR, PDR and NPDR in Asian T2DM patients. Effect size (ES) with 95% confidence interval (CI) was used to evaluate the prevalence of DR, PDR and NPDR in Asian T2DM patients, respectively., Results: There were 41 references and 48 995 T2DM patients involved in this study. The prevalence of DR, PDR, and NPDR was 28%, 6%, and 27% in T2DM patients, respectively; while the prevalence of PDR and NPDR in DR patients was 17% and 83%, respectively. Subgroup analysis showed that prevalence of DR in T2DM patients from Singaporean, Indian, South Korean, Malaysian, Asian, and Chinese was 33%, 42%, 16%, 35%, 21% and 25%, respectively. In T2DM patients with NPDR from Indian, South Korean, Malaysian, Asian, Chinese, higher prevalence was found than that in PDR patients (45% vs 17%, 13% vs 3%, 30% vs 5%, 23% vs 2% and 22% vs 3%), as well as in DR patients (74% vs 26%, 81% vs 19%, 86% vs 14%, 92% vs 8% and 85% vs 15%). The prevalence of PDR in T2DM from India was higher than patients from other locations of Asia, and the same results were also observed in NPDR patients., Conclusion: In either T2DM Asian patients or DR patients, NPDR is more common than PDR. Based on our results, we should pay more attention to NPDR screening and management in T2DM patients, and we also recommend suitable interventions to prevent its progression.

Aim: To investigate protective effects of a novel recombinant decoy receptor drug RC28-E on retinal damage in early diabetic rats., Methods: The streptozotocin (STZ)-induced diabetic rats were randomly divided into 6 groups: diabetes mellitus (DM) group (saline, 3 µL/eye); RC28-E at low (0.33 µg/µL, 3 µL), medium (1 µg/µL, 3 µL), and high (3 µg/µL, 3 µL) dose groups; vascular endothelial growth factor (VEGF) Trap group (1 µg/µL, 3 µL); fibroblast growth factor (FGF) Trap group (1 µg/µL, 3 µL). Normal control group was included. At week 1 and 4 following diabetic induction, the rats were intravitreally injected with the corresponding solutions. At week 6 following the induction, apoptosis in retinal vessels was detected by TUNEL staining. Glial fibrillary acidic protein (GFAP) expression was examined by immunofluorescence. Blood-retinal barrier (BRB) breakdown was assessed by Evans blue assay. Ultrastructural changes in choroidal and retinal vessels were analyzed by transmission electron microscopy (TEM). Content of VEGF and FGF proteins in retina was measured by enzyme linked immunosorbent assay (ELISA). The retinal expression of intercellular cell adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), VEGF and FGF genes was examined by quantitative polymerase chain reaction (qPCR)., Results: TUNEL staining showed that the aberrantly increased apoptotic cells death in diabetic retinal vascular network was significantly reduced by treatments of medium and high dose RC28-E, VEGF Trap, and FGF Trap (all P <0.05), the effects of medium and high dose RC28-E or FGF Trap were greater than VEGF Trap ( P <0.01). GFAP staining suggested that reactive gliosis was substantially inhibited in all RC28-E and VEGF Trap groups, but the inhibition in FGF Trap group was not as prominent. Evans blue assay demonstrated that only high dose RC28-E could significantly reduce vascular leakage in early diabetic retina ( P <0.01). TEM revealed that the ultrastructures in choroidal and retinal vessels were damaged in early diabetic retina, which was ameliorated to differential extents by each drug. The expression of VEGF and FGF2 proteins was significantly upregulated in early diabetic retina, and normalized by RC28-E at all dosages and by the corresponding Traps. The upregulation of ICAM-1 and TNF-α in diabetic retina was substantially suppressed by RC28-E and positive control drugs., Conclusion: Dual blockade of VEGF and FGF2 by RC28-E generates remarkable protective effects, including anti-apoptosis, anti-gliosis, anti-leakage, and improving ultrastructures and proinflammatory microenvironment, in early diabetic retina, thereby supporting further development of RC28-E into a novel and effective drug to diabetic retinopathy (DR).