Posterior vitreous detachment (PVD) is the separation of the posterior vitreous cortex from the inner surface of the retina and occurs on the basis of aging and liquefaction of the vitreous. Risk of posterior vitreous detachment: The vitreous has separated from the retina, but is still adhered tightly at the close connection with the retina. With the posterior eye movement, the floating posterior vitreous cortex exerts a pulling force on the retina, and there is a risk of retinal fissure. However, the vitreous body is a component of the refractive media of the eye and has a supporting, shock-absorbing and nutritive effect on the lens and retina. Therefore, it is not recommended to remove all the vitreous in the posterior detachment, unless there is a hole-derived retinal detachment occurring. As long as regular review and observation, when retinal degeneration and fissure are found, timely sealing of retinal degeneration area and fissure with laser will be sufficient.