Oxidative stress occurs due to an imbalance between the systemic manifestation of the reactive oxygen species (ROS) and the biological system's ability to repair the subsequent damage or detoxify the reactive intermediates. The disturbances in the redox state of cells may lead to toxic effects by producing free radicals and peroxides, which harm all components of the cells, such as DNA, proteins, and lipids. Oxidative stress occurring due to oxidative metabolism causes strand breaks in DNA along with base damage. ROS generated hydrogen peroxide, superoxide radical and hydroxyl radical causes base damage indirectly. Oxidative stress is known to contribute to diabetes and its complications such as retinopathy. Diabetic patients with retinopathy are prone to acquired blindness. Oxidative stress can lead to development of proliferative diabetic retinopathy (PDR), also called diabetic macular edema, which may lead to visual impairment in DR patients. This book provides comprehensive insights on the role of oxidative stress in diabetic retinopathy. It will serve as a reference to a broad spectrum of readers.