Inflammatory Biomarkers in Diabetic Macular Edema

Diabetic retinopathy (DR) is a major complication of both Type 1 and Type 2 diabetes mellitus (T1DM and T2DM). Disease progression can result in visual impairment, primarily due to diabetic macular edema (DME) or proliferative diabetic retinopathy (PDR). Although several ocular treatments are available for DME, a subset of patients fails to respond, reflecting the multifactorial, complex, and systemic nature of DR. Inflammatory biomarkers can be classified according to different characteristics, including imaging biomarkers-most commonly assessed using optical coherence tomography (OCT)-and molecular biomarkers, which are defined by their biochemical and biophysical properties. Pro- and anti-inflammatory cytokines, chemokines, adipokines, and inflammation-related enzymes are recognized as key inflammatory biomarkers and can be detected in the vitreous humour, aqueous humour, tears, serum, and other biological tissues. The identification and characterization of reliable biomarkers may help determine disease severity, monitor disease progression, and predict the risk of specific outcomes, thereby aiding in the prevention of end-stage disease (prognostic biomarkers). In addition, biomarkers may serve as predictive tools for therapeutic response, guiding personalized treatment strategies and enabling ongoing monitoring. This review provides a comprehensive overview of the role of inflammatory biomarkers in the diagnosis and management of DR and DME.