Choroidal neovascularization, also known as subretinal neovascularization, is a proliferative blood vessel from the choroidal capillaries. It expands through the rupture of Bruch's membrane and proliferates between Bruch's membrane and retinal pigment epithelium, or between neural retina and retinal pigment epithelium, or between retinal pigment epithelium and choroid. It is more common in the macula, thus seriously damaging central vision. This disease is extremely common and has become one of the main causes of blindness. Early detection and timely treatment are of great clinical significance. As early as 1876, Sattle noticed in histological examinations of normal adult eyes that half of the people had neovascularization between the peripheral part of the retina and Bruch's membrane. Reichling et al. have confirmed that this type of capillary network often appears in the peripheral part of the fundus. Friedman et al. used enzyme digestion technology to find that neovascularization appeared between Bruch's membrane and retinal pigment epithelium in the ora serrata area, which is common in adult eyes, and especially common in people over 60 years old.