Oxidative Stress and Diabetic Retinopathy

Abstract

Oxygen metabolism is essential for sustaining aerobic life, and normal cellular homeostasis works on a fine balance between the formation and elimination of reactive oxygen species (ROS). Oxidative stress, a cytopathic consequence of excessive production of ROS and the suppression of ROS removal by antioxidant defense system, is implicated in the development of many diseases, including Alzheimer's disease, and diabetes and its complications. Retinopathy, a debilitating microvascular complication of diabetes, is the leading cause of acquired blindness in developed countries. Many diabetes-induced metabolic abnormalities are implicated in its development, and appear to be influenced by elevated oxidative stress; however the exact mechanism of its development remains elusive. Increased superoxide concentration is considered as a causal link between elevated glucose and the other metabolic abnormalities important in the pathogenesis of diabetic complications. Animal studies have shown that antioxidants have beneficial effects on the development of retinopathy, but the results from very limited clinical trials are somewhat ambiguous. Although antioxidants are being used for other chronic diseases, controlled clinical trials are warranted to investigate potential beneficial effects of antioxidants in the development of retinopathy in diabetic patients.

Induction of Ischemic Tolerance Protects the Retina From Diabetic Retinopathy

“…1 Vision loss occurs due to chronic hyperglycemia, vascular damage and leakage, edema, capillary basement membrane thickening, neovascularization, hemorrhage, and ischemia. 2 Although the pathogenesis of DR is highly complex and not fully understood, VEGF is recognized as a major contributor to the development of DR. 3 Despite the attempts to control blood glucose levels, many diabetic patients are affected by DR, which progresses to more severe forms of disease. Because available treatments are not very effective, it is imperative to develop better approaches for DR prevention and treatment.…”

Diabetes Mellitus: Role of Free Radicals and Oxidative Stress

“…However, the exact mechanism by which oxidative stress may contribute to the development of diabetic complications is undetermined. [96] In the past few decades, increasing evidence has connected oxidative stress to a variety of pathological conditions, including cancer, cardiovascular diseases (CVDs), chronic inflammatory disease, post-ischemic organ injury, diabetes mellitus, xenobiotic/drug toxicity, and rheumatoid arthritis. [97,98] Over time, convincing evidence has established the role of free radicals and oxidative stress in the pathogenesis and development of complications from DM [99] including retinopathy, nephropathy, neuropathy and accelerated coronary artery disease.…”

Effect of Diabetes on the Rat Renal Cortex and the Possible Protective Role of Vitamins C and E

“…[1] Diabetes mellitus (DM) is a metabolic condition which results from inability of the pancreas to produce adequate amounts of insulin, or insensitivity of the cells of the body to insulin effects, thus resulting in unusually elevated blood glucose levels (hyperglycaemia). [2,3] Insulin resistance and chronic hyperglycaemia lead To various long-term problems and complications such as autonomic neuropathy, peripheral neuropathy and nephropathy. [2,4] Diabetic kidney disease (DKD) is defined as functional, structural and clinical alterations of the kidneys caused by diabetes.…”