By the term diabetic retinopathy we refer to an eye disease which is found in most patients with diabetes mellitus, especially of type 1 (insulin-dependent). Those who suffer from this type of diabetes are about twenty times more likely to develop damage to the retina and other ocular structures.
Most often it affects people with diabetes aged between 25 and 60 years and typically occurs in the first diabetic phase; however, the chances of developing the disease increase exponentially when the disease was contracted at least ten years earlier.
Diabetics suffer from to blood vessel injury, in particular affecting the microcirculation in various organs (mainly kidneys, heart, brain and eyes). This damage involves a lack of adequate blood supply (and, hence, oxygen) to certain areas of the retina, which consequently undergo an impairment (i.e. become ischemic); before this happens, they release a growth factor of new blood vessels (VegF), which induces their uncontrolled proliferation: this greatly harms the retinal tissue, thereby causing a significant decline in vision.
Diabetic retinopathy can be distinguished, based on the presence or absence of newly formed vessels, between a proliferative form (considered more severe) and a non-proliferative form. The former is characterized by the presence of an intense vascular proliferation, with extremely fragile blood vessels (so thus very often tend to rupture, causing retinal damage): the symptoms of diabetic retinopathy are, in general, impaired vision (reduction in visual acuity up to low vision or even blindness), while the latter (non-proliferative form) does not involve this proliferation of new vessels, but only microaneurysms (which affect both small retinal vessels and vessels of larger calibre) and sometimes the presence of exudates (with protein, lipid and carbohydrate deposits that also tend to have a negative effect on vision). However, it may happen that the less severe form (non-proliferative) degenerates into the proliferative form.