neovascular

Neovascular is an adjective describing tissue that contains newly formed blood vessels or processes that generate new vasculature. Neovascularization refers to the growth of new vessels from preexisting vasculature (angiogenesis) or from endothelial progenitors (vasculogenesis). The process is usually driven by hypoxia, inflammation, and tissue injury, and is regulated by a balance of pro-angiogenic and anti-angiogenic factors. Common mediators include vascular endothelial growth factor (VEGF), fibroblast growth factors, and matrix metalloproteinases that remodel the extracellular matrix. Neovascular vessels are often immature and leaky, which can impair tissue function when abnormal.

In ophthalmology, retinal neovascularization occurs in diseases such as proliferative diabetic retinopathy and retinal vein occlusions, and iris neovascularization can cause neovascular glaucoma. These vessels can bleed and form scar tissue that distorts vision or blocks fluid drainage. Diagnosis uses fundus examination, fluorescein angiography, and optical coherence tomography. Treatments include anti-VEGF injections, laser photocoagulation, or surgical interventions to remove abnormal vessels or reduce pressure.

In oncology, tumors frequently stimulate neovascularization to supply oxygen and nutrients; this process is central to tumor growth and metastasis. Anti-angiogenic therapies that inhibit VEGF signaling can slow tumor progression but may be associated with hypertension, thromboembolism, wound healing impairment, and other adverse effects.

In wound healing and tissue regeneration, neovascularization is essential for delivering inflammatory cells and oxygen to damaged areas. Abnormal or excessive neovascularization can contribute to chronic wounds or scarring.