Vascularization, Angiogenesis
Angiogenesis is the process whereby new vessels form from pre-existing vessels. The growth of new blood vessels promotes embryonic development, wound healing, female reproductive cycle, and plays a key role in the pathological development of solid tumor cancers, hemangiomas, diabetic retinopathy, age-related macular-degeneration, psoriasis, rheumatoid arthritis, gingivitis, and possible osteoarthritis and inflammatory bowel disease.
Corneal Vascularization
The normal cornea does not have blood vessels and the development of corneal vascularization is a complex event. Potential causes of new vessel growth in a previously avascular (with no blood vessels) are linked to trauma or chronic eye conditions. Although patients may be asymptomatic, corneal vascularization must be avoided as vessel ingrowth can lead to subsequent vision loss due to inflammation and lipid deposition in the cornea.
The prognosis for recovery from vascularization is excellent, although residual "ghost" vessels in the cornea may remain many months or even years after [lens] refitting.1
Neovascularization
Neovascularization is the process by which new blood vessels develop in tissues. Tumors in order to grow beyond 10 cubic millimeters require formation of new blood vessels. The recruitment of new blood vessels by a tumor is a multistep process and the factors involved in each step have been the subject of intense investigation.2
New blood vessels can grow in tumors by sprouting from pre-existing vessels or by recruitment of circulating bone marrow-derived endothelial progenitor cells. Several cell types within tumors, including tumor cells, monocytes and fibroblasts, secrete growth factors, such as VEGF that induce blood vessel growth into tumors .3
Studies have shown that angiogenesis plays a major role in tumor growth and that inhibiting angiogenesis can inhibit tumor progression and metastasis.3
References:
1. The cornea: its examination in contact lens practice. Nathan Efron
2. New Research on Angiogenesis Inhibitors. Elmer T. Skinard
3. Antiangiogenic agents in cancer therapy. Beverly A. Teicher, Lee M. Ellis
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