Anti-VEGF therapies have been widely used in the treatment of age-related macular degeneration, diabetic macular edema, retinal vein occlusion with macular edema and other retinal diseases. It have achieved remarkable treatment effect with relatively high safety, but there are still reports of adverse reactions in cardio-cerebral vessels and eyes. There are many methods to measure retinal blood flow. Although the principles of these methods are different, the results are different, and there is no uniform standard, it has been observed that anti-VEGF drugs may cause some changes in retinal vessel diameter, arterial blood flow velocity and blood flow parameters. Especially after multiple injections, the effect may be more obvious.