What are the diseases associated with abnormal angiogenesis?

Uncontrolled angiogenesis can lead to several angiogenic disorders such as atherosclerosis, arthritis, vascular insufficiency and vascular overgrowth. It is known that tumors are highly vascular in nature. Thus, tumor angiogenesis is positively correlated with tumor malignancy. In diabetic retinopathy, there is a loss of pericytes, which causes subsequent capillary regression along with the formation of microaneurysms and vascular leakage. These abnormalities cause retinal ischemia, which promotes angiogenesis, resulting in insufficient retinal perfusion and hemorrhage. In atherosclerosis, specific conditions such as oxidative stress and anoxia,  generate angiogenic factors which promote sprouting angiogenesis from preexisting blood vessels. Angiogenesis is also involved in the onset of arthritis, with VEGF playing a significant role in the process. It has been shown that serum levels of the soluble form of the VEGF flt-1 receptor are raised in rheumatoid arthritis.