"Signs and Symptoms of Diabetic Retinopathy" is a significant example of a paper on the cardiovascular system. Diabetic Retinopathy is characterized by alterations that take place within the blood vessels of the retina, as the available vessels swell and leak fluids while new vessels abnormally grow on the surface of the retina, resulting in indistinct visions (Brenchley et al, 2004). The angiogenic stimulators lose their sense of balance following the overproduction of VEGF and the underproduction of PDF (Gao et al, 2006). The change in equilibrium brings about the breakdown of the blood-retinal barrier, an event that results in the overmultiplying of the retinal endothelial cells. The over multiplying of the capillary endothelial cells is responsible for the formation of additional blood vessels within the retina, which is one of the major symptoms of diabetic retinopathy. The increase in VEGF to PDF ratio that comes about due to overproduction of VEGF and under the production of PDF, is similarly responsible for the leaking of various fluids among them blood from the capillaries into the retina.
This is brought about by the fact that extreme production of VEGF and low production of PEDF induces vascular permeability of the epithelial cells, an event that makes the blood vessels highly permeable, hence prompting leakage of blood; a condition referred to as intraretinal hemorrhage and that of other fluids known as macula edema.
Macular edema affects the central region of the retina that is responsible for comprehensive central vision (Aiello et al, 2006). Several studies have likewise revealed that equilibrium loss among the angiogenic stimulators is responsible for the occurrence of eye microaneurysms, which come about due to swelling of the vascular cells brought about by the protrusion of either an artery or a vein.