A non-invasive, multi-target approach to treat diabetic retinopathy

Hyperglycemia invoke number of pathways resulting in development of diabetic retinopathy (DR), including protein kinase C activation, increased expression of VEGF, advanced glycation end product (AGEs) formation and activation of polyol pathway, among which the pathophysiology of aldose reductase (ALR2) of the polyol pathway is evident by more than a decade of research. Subtle involvement of ALR2 in invoking various pathways of diabetic complications has caused an increase in attention towards the identification of novel aldose reductase inhibitors (ARIs). Numerous ARIs of different classes were employed in the treatment of diabetic complications initially, but few came into light as drugs. Though no ALR2 inhibitor has been used for the treatment or control of DR, Epalrestat has been used worldwide for treating diabetic neuropathy. This review critically analyses different treatments available for diabetic retinopathy, their limitations and the importance of the development of novel inhibitors of ALR2 that could prevent progression of DR, by causing a direct or indirect effect on controlling factors associated with DR.