High vitreous TNF-Alpha and vascular endothelial growth factor levels as a risk factor for proliferative diabetic retinopathy in type 2 diabetes mellitus patients

Introduction: Type-2 diabetes mellitus is a metabolic disease that can cause various complications. One of the complications of type 2 DM that can occur in the eyes is Proliferative Diabetic Retinopathy (PDR). PDR can cause a sharp decrease in vision and even blindness. The global prevalence of DM is 8.3%, and the prevalence of DM in Bali is 5.9%. PDR complications occurred in 26.3% of type 2 DM patients. Therefore, this study aims to prove the role of TNF-alpha in the inflammatory pathway and the role of VEGF in the angiogenesis pathway as risk factors for PDR in type 2 DM. Methods: This study is a case-control study, and matching is carried out for age and gender. A total of 38 subjects were enrolled in this study, where the case group was type 2 DM patients with PDR who underwent vitrectomy, and the controls were patients without type 2 DM who underwent vitrectomy according to medical indications. The levels of TNF-alpha and VEGF in the vitreous were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) technique. Result: TNF-alpha and VEGF's cut-off points are 15.795 pg/ml and 22.980 pg/ml. OR of TNF-alpha was 5.13; 95% CI: 2.88-6.95; p= 0.001 (<0.05). OR of VEGF was 3.86; 95% CI: 1.83-3.79; p=0.017 (<0.05). The multinominal logistic regression analysis test showed that OR TNF-alpha was dominant as a risk factor for PDR, followed by VEGF. OR TNF-alpha=5.88; 95% CI: 2.36-6.79; p=0.008 (<0.05). OR VEGF= 3.1; 95% CI: 1.02-3.37; p=0.015 (<0.05). Conclusion: This study proves that high vitreous levels of TNF-alpha and VEGF are risk factors for PDR in type 2 DM. These findings strengthen the theory of PDR pathogenesis through the inflammatory pathway (TNF-alpha) and the angiogenesis pathway (VEGF) in type 2 DM.