Pathologic neovascularization is caused by an hypoxia condition, i.e. by poor oxygenation, induced by the presence of one or more ischemic areas in the retina. Should this be the case, the eye “responds” promoting the growth of new “immature” blood vessels, which present a particularly fragile altered structure and for this reason they are referred to as pathologic new vessels.
The pathologic new vessels are not able to efficiently oxygenate the retinal tissue, they conversely damage it. As a matter of fact they can cause hemorrhages or accumulation of plasma at the retinal level, leading to the formation of a pseudo-fibrotic tissue and pathological new vessels can lead to a vitreo-retinal proliferation and to the formation of fibrovascular membranes, i.e. pseudo-scar membranes, which shrink over time, deforming the retinal profile and causing a distorted vision and a reduction of vision. If the fibrovascular membranes appear in the more central part of the retina, they can give rise to the appearance of dark areas (scotomas) in the visual field or even to the loss of the central vision.