This is when abnormal blood vessels grow inside the eye. The eye is a very metabolically active organ. It continuously works and detects light, even while sleeping. In some ways the eye works like the heart … in the sense that it is “always on.” As such, the eye, especially the retina, requires a rich blood supply to function properly. The retina doesn’t have a collateral blood supply. It only gets its blood and oxygen nourishment from a couple of sources. If there is a disruption to this blood supply, the retina quickly becomes starved for oxygen and can die. Many things can disrupt the blood flow to the eye. Diabetic retinopathy, blood clots, and macular degeneration can interfere with the blood supply to the retina. In all of these cases, the retina becomes “hungry” for oxygen and responds by pumping out “vascular endothelial growth factors” or VEGFs. These are natural hormonal stimulants for the growth of new blood vessels inside the eye. Normally, this would be great as new blood vessels could bring in fresh blood and keep the retina well-nourished, but it doesn’t work this way. The new blood vessels grow quickly and are abnormal, with a tendency to leak, bleed, and contract causing vitreous hemorrhages, macular edema, and even retinal detachments. It is the VEGFs that cause neovascularization. To combat neovascularization, eye doctors try to decrease VEGF production. PRP laser can be performed to destroy these tissues. For more localized neovascularization at the macula, anti-VEGF injection medicines like Avastin are now being used extensively in the eye and this has drastically improved the treatment for “wet” macular degeneration.