Diabetic Retinopathy

Abstract

Diabetic retinopathy (DR) is the leading cause of vision loss and blindness in people of working age. Alarmingly, the number of people with DR and those that progress to the vision-threatening forms of the disease, proliferative DR (PDR) and diabetic macula oedema (DME) is increasing across the globe. Current treatments focus on PDR and DME and include anti-angiogenic and anti-vascular permeability agents administered into the eye. However, there remains an urgent need to develop treatment approaches that are more effective and also prevent advancement of the disease. Traditionally, DR is considered a disease of the retinal microvasculature visible by ophthalmoscopy. It is now appreciated that a neurovascular unit exists in the retina comprised of interactions between vascular cells (endothelial cells and pericytes), as well as glia, neurons and resident immune cells, which become damaged by diabetes-induced hyperglycaemia and tissue ischaemia. Some of the pathological pathways underpinning injury to the retinal neurovascular unit have been identified and include vasoactive factors, advanced glycation end products, oxidative stress and inflammation.