Diabetic Retinopathy: Its Mechanism and Therapeutic Strategies

Today, diabetes as a result of its many complications such as retinopathy, nephropathy, neuropathy and cardiovascular problems is attracting much attention as a global pathology. Diabetic retinopathy is a major cause of adult blindness in the world, as reported by the World Health Organization, with a prevalence estimated to double by 2030. Diabetic retinopathy can be categorized as two types, proliferative- and non-proliferative diabetic retinopathy. Based on literature available, 20-50% of patients with long duration of diabetes, are mostly diagnosed with the proliferative form of retinopathy, a disorder caused by activation of biochemical pathways associated with hyperglycemia and ultimately increased oxidative stress, inflammation, and nerve damage, resulting defects in micro-vessels of the retina, eventually which can lead to vision loss and blindness. Hence due to the increased production of free radicals and active oxygen species (ROS), and also defects in the antioxidant defense system in this disease, natural antioxidants, such as plant flavonoids can be effective in reducing harmful oxidative stress. Currently the use of medicinal plants and their active components is a field of interest in the treatment of diabetes and its complications. Based on the results of several studies on the use of natural products in treatment of diabetes, antioxidants could be used to design new drugs with lower side effects.