The reason wet age-related macular degeneration (AMD) causes vision loss is that the retina starts to be invaded by new, abnormal, leaky blood vessels, which put excess fluid into the retina, making it swell. One of the main drivers of this blood vessel growth is a protein called VEGF – vascular endothelial growth factor. Over the past 15 years, several drugs have been developed that can block the action of VEGF, reducing swelling, and at least partially restoring vision or stabilizing disease progression.
Anti-VEGF drugs are large molecules, and cannot be administered by oral pills or by eyedrops; instead, they have to be injected into the eye so that they act exactly where they are needed. These injections are into the vitreous, in front of the retina, and this method of administering the drug is called intravitreal (IVT) injection.
Intravitreal Injections (IVT) explained