Composite fluorescein angiogram of the retina of the right eye of a male patient where severe damage to the retina has been caused by diabetes (diabetic retinopathy). Blood vessels emerging from the optic disc have become blocked due to diabetes and have started to haemorrhage (bleed, bright white areas). This has caused a reduction in blood flow to other areas of the retina, leading to the proliferative growth of new capillaries. These new capillaries are pulling on the retina and have separated it from the back of the eye, a condition known as tractional retinal detachment. Diabetic retinopathy may lead to blindness if left untreated. Bleeding can be treated by laser photocoagulation, and blood sugar level maintenance can slow the disease's progress.