I. The vitreous body is originally a non-vascular gel-like tissue, usually due to pathological changes in the adjacent tissues, resulting in blood entering the vitreous cavity and introducing vitreous blood accumulation. The entry of blood into the vitreous changes the transparency of the vitreous and promotes vitreous degeneration. There are many causes of vitreous hemorrhage. In addition to trauma and surgical factors, common causes include: 1. retinal vascular diseases such as proliferative diabetic retinopathy, retinal vein obstruction, retinal vasculitis, etc. 2, intraocular inflammatory diseases As inflammation leads to the destruction of the blood-retinal barrier, blood can enter the vitreous: it can also be caused by inflammation leading to vitreous degeneration, which causes secondary contraction of vitreous traction and tearing of the retinal vessels causing hemorrhage. Such as partial infectious endophthalmitis Behcet, acute retinal necrosis syndrome (ARN), etc. 3.Some aging diseases and congenital conditions cause subretinal neovascular membrane (CNV) proliferation type of diseases, such as age-related macular degeneration (AMD), retinal fissure on the vascular bridge rupture hemorrhage, congenital retinal fissure, congenital retinal folds, etc. 4. Intraocular tumors such as retinal hemangioma, etc. Diagnostic criteria 1, a small amount of vitreous hemorrhage when the patient’s vision is not significantly affected, but there are more mosquito-like symptoms appear. But a large number of vitreous hemorrhage patients have rapid and serious vision loss, and even patients can describe the whole process of the onset in detail. 2, slit lamp and anterior microscopy can be found in the vitreous body with bright red or mixed yellow degeneration of blood shadow cells. 3.Patients with small amount of hemorrhage can see the primary disease of the retina, but patients with large amount of hemorrhage cannot see the fundus lesion, or even only the red and black reflection. 4.B ultrasound can understand the degree of vitreous blood accumulation, the state of the retina and the interrelationship of the vitreoretinal, which helps to judge the primary disease and the choice of treatment. 5.Electrophysiological examination of vision helps to understand the functional status of optic nerve and retina and judge the prognosis. 6. Detailed examination of the status of the contralateral eye helps to judge the cause of hemorrhage. III. Treatment principles 1. Patients with low bleeding volume are mainly treated for the primary disease. In the early stage, Chinese herbal medicines can be used to promote the absorption of the accumulated blood, and in the late stage, iodine can be used to help the absorption of vitreous opacities. 2.For patients whose cause of bleeding and retinal status are not clear, while promoting the absorption of blood in the vitreous, regular and strict follow-up should be carried out, and the status of the retina should be grasped through fundoscopy or ultrasound examination, and once retinal detachment is found, surgery should be carried out in time. 3, for patients with large amount of bleeding, intravitreal blood is difficult to absorb, and often causes serious degeneration of the vitreous, so after short-term treatment (2 weeks after the onset is appropriate) is ineffective, vitreous surgery can be considered. Fourth, the cure criteria vitreous blood absorption, refractive interstitial improvement, the original cause of bleeding is controlled.