Association between early inflammation and neurodegeneration in diabetic retinopathy: a narrative review

Diabetic retinopathy (DR) is a severe complication of diabetes that leads to vision loss. Neovascularization, inflammation, and neurodegeneration have been recognized as its primary pathogenic mechanisms. Over the past decades, with the emergence of novel technologies and drugs, the treatment of DR has advanced rapidly, particularly anti-vascular endothelial growth factor (VEGF) therapy, which has demonstrated unique efficacy. However, current treatments for DR predominantly focus on the progressive stages of the disease. Timely intervention during the early stages of DR to prevent vision loss remains an urgent unmet need. This paper reviews recent literature on the early pathogenic processes of DR and reveals that early inflammation can impair the structure and function of the neural retina, while neurodegeneration exacerbates inflammatory progression to some extent. Moreover, both share common initiating factors. Therefore, this study proposes that an interaction between inflammation and neurodegeneration exists in the early stages of DR, forming a pathological loop. Understanding this interaction could significantly enhance our comprehension of DR pathogenesis and facilitate the identification of more effective therapeutic targets, ultimately improving the prognosis of DR.