2Diabetic Retinopathy Causes
Before talking about the signs and symptoms we need to know how this complication appears. If your blood sugar levels are too high for a long period of time, the small blood vessels located in your retina will get weaken and damaged, until its blockage, not letting the nutrients pass and cutting off its blood supply.
This process produces several changes in the retina, which at the same time produces more local complications, affecting the vision. If this damage continues, the affectation will be major, possibly leading to blindness.
Some of the changes include the growth of new blood vessels to substitute the damaged ones. In this case, the new blood vessels will not develop in the right way, starting to weaken and leaking fluid (hemorrhages or exudates) into the retina. Due to the inflammatory process that may develop in the retina, scar tissue appears and it can increase the pressure inside your eye, causing your retina to detach.
In this image are shown two kind of eyes. The one at the left is a normal and healthy eye, viewing its structures and especially the blood vessels, which enter and exit from the optic nerve. The eye at the right shows signs of diabetic retinopathy with hemorrhages and exudates due to the leaking of the blood vessels. This is one of the reasons that affects vision in diabetic patients.