The hallmark of diabetic retinopathy is that high glucose and other stressors damage the small blood vessels and capillaries of the eyes. High circulating glucose levels leads to endothelial cell and pericyte uncoupling and capillary break-down with resulting regional areas of ischemia in the back of the eye. Importantly, these areas of capillary breakdown represent damaged retinal tissue resulting permanent vision loss. Although patients may not notice this initially in the early stages of disease, these lesions functionally result in damaged peripheral vision and reduced night vision.
In more advanced stages of the disease, vascular leakage and diabetic macular edema (DME) may cause significant impairment of the central vision and if left untreated permanent vision loss may continue to progress into blindness.
Based on the global high prevalence of diabetes and the limited availability of effective disease control and treatments, diabetic retinopathy is today the leading cause of blindness in working age adults.