Vitreous surgery is a microsurgical procedure that was developed in the 1970s. Its advent is considered an important milestone in the history of ophthalmic treatment, enabling the treatment of many eye diseases that were previously considered incurable. With the emergence of new concepts, instruments, and techniques, the indications for surgery continue to expand, and vitreous surgery has become the second major ophthalmic surgery after cataract extraction IOL implantation in eye centers in developed countries. Indications for vitrectomy of the posterior segment of the eye: 1. Vitreous hemorrhage: It is a major indication for vitrectomy. When vitreous hemorrhage is not absorbed after conservative treatment, vitrectomy should be performed. However, surgery should be performed promptly once retinal detachment is observed. Traumatic vitreous hemorrhage surgery can be performed two weeks after the trauma. 2, intraocular foreign body: vitrectomy to remove foreign body is performed under direct vision, especially for non-magnetic foreign body, or when accompanied by other eye tissue damage, it is easy to handle together. 3, intraocular inflammation: surgery can remove bacteria and their toxins, remove necrotic tissue and inflammatory material, and inject drugs directly into the vitreous cavity, while taking vitreous fluid for pathogen culture and drug sensitivity test. 4.Complex retinal detachment: combined with vitreous opacities. Giant fissure, multiple fissures, posterior pole fissures combined with proliferative vitreoretinal lesions, tractional retinal detachment caused by vitreous proliferation, recurrent retinal detachment. It can effectively close all the fissures to achieve stable retinal repositioning. 5.Proliferative diabetic retinopathy: severe non-absorbing vitreous hemosiderosis, traction retinal detachment combined with early macular traction, mixed retinal detachment, dense preretinal hemorrhage combined with pre-macular, severe progressive retinal fibrovascular proliferation, vitreous hemosiderosis combined with early iris neovascularization, cataract combined with vitreous hemosiderosis, hemolytic glaucoma. 6, macular diseases: vitreous macular traction syndrome, idiopathic macular fissure, secondary or idiopathic macular surface membrane. 7.Other.