Oxidative Stress in Diabetic Retinopathy: A Comprehensive Review of Mechanisms, Biomarkers, and Therapeutic Perspectives.

Diabetic retinopathy (DR) is a leading cause of vision loss globally and represents one of the most common microvascular complications of diabetes. In addition to metabolic disturbances associated with hyperglycemia, oxidative stress has emerged as a critical contributor to the onset and progression of DR. Oxidative stress, defined as an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms, leads to cellular injury, inflammation, and increased vascular permeability. In the diabetic retina, excessive ROS production promotes endothelial cell apoptosis, breakdown of the blood-retinal barrier (BRB), and induction of angiogenic factors such as vascular endothelial growth factor (VEGF). This review provides a comprehensive overview of the pathophysiology of DR, focusing on the molecular mechanisms of oxidative stress. Relevant studies were identified through a structured search of PubMed, Web of Science, and Scopus (2000-2025) using terms such as 'diabetic retinopathy', 'oxidative stress', and 'antioxidants'. We explore current knowledge on oxidative stress-related biomarkers and therapeutic strategies targeting oxidative damage, including antioxidant compounds and mitochondrial protective agents. Recent findings from both experimental and clinical studies are summarized, highlighting the translational potential of oxidative stress modulation in DR management. Finally, future research directions are discussed, including biomarker standardization, personalized medicine approaches, and long-term clinical validation of antioxidant-based therapies. A deeper understanding of oxidative stress may offer valuable insights into novel diagnostic and therapeutic strategies for DR.