A Review on Research Methodologies of Diabetic Retinopathy
Cataract, opacity of the eye lens is a major complication of chronic diabetes leads to loss of vision and is the leading cause of blindness worldwide. Nearly 19 million people are blind due to cataract in the world. It is a result of increased polyol pathway activity, activation of protein kinase C (PKC), increased oxidative stress, and accumulation of advanced glycation end products (AGEs) due to prolonged hyperglycemia. In vitro and In vivo studies have suggested that the damage to lens is a result of oxidation and generation of free radicals. The antioxidants enzymes might protect the lens against the formation of cataract. Several invasive and non-invasive research methodologies have been in proceeding for the study of diabetic retinopathy. The research methodologies for retinal examinations that improve the cost-effectiveness and noninvasive, allows repeated assessment, and can be performed in a relatively short period of diabetic retinopathy were discussed in this review. Several image processing based methods have been developed in the last decade providing an alternative to first phase examinations by using slitlamp examination and fundoscopy of lens. Estimation of antioxidant enzymes like superoxide dismutase, catalase, aldose reductase, reduced glutathione and glutathione peroxidase and protein products such as malonaldehyde, sorbitol, α-crystalline, protein carbonyl content and estimation of advanced glycation end products and several inflammatory mediators by various approaches were discussed in the present review.