(1) etiology
1. Arterial insufficiency 1965. According to animal experiments, Hayerh proposed that insufficient arterial blood supply is a prerequisite for central retinal vein occlusion. In animal experiments, if we only block the central vein, we can't produce typical fundus changes. Only by blocking the blood supply of the central artery at the same time can we produce a series of typical lesions. The same is true when the branch of retinal vein is blocked, but its involvement is limited to the supply area of this branch.
2. Changes of vascular wall When middle-aged and elderly people suffer from vascular sclerosis, the vein at the intersection of arteriovenous or sieve plate is compressed by the hardened artery, resulting in slow and stagnant blood flow here. Young patients can damage the blood vessel wall due to venous vasculitis, resulting in blocked blood flow.
3. The change of blood viscosity is due to the change of plasma protein quality, such as macroglobulinemia; Or changes in blood components, such as polycythemia; Leukemia and sickle cell anemia.
(2) The performance of prison beds
The main symptom is the decrease of central vision, or the defect of a certain part of visual field, but the onset is far less acute and serious than arterial occlusion, and generally some vision can be preserved. About 5-20% of patients can develop iris neovascularization and secondary neovascular glaucoma 3-4 months after central vein occlusion.
When the central retinal vein is blocked, extensive bleeding can be seen in the fundus, which can be radial, flame-shaped, round or enter the vitreous body. The optic disc is edema, the boundary is blurred, the surface is often covered by bleeding point, and the retinal vein is twisted and swollen, purple-red, which is often buried by edema or bleeding point. If it's intermittent, it looks like sausage. Arterial stenosis, no venous pulsation when pressing the eyeball. Edema can still appear in the retina in the early stage, and then there will be gray cotton-wool exudation points. If mixed with the bleeding point, complex morphological fundus changes can be formed. In the late stage, the optic disc showed secondary atrophy and arteriovenous thinning. Bleeding and exudates can be absorbed, leaving irregular pigmentation, and sometimes new blood vessels appear around the optic disc and affected veins. If it is incomplete occlusion or branch occlusion, the lesion is light and limited to a part of the fundus. Branch vein occlusion is mainly seen at the junction of artery and vein, and the decrease of vision is mainly due to macular edema, retinal hemorrhage and ischemia, which can cause retinal neovascularization.
The early manifestations of branch vein occlusion are: ① strong fluorescence leakage at the occlusion; ② Fluorescent perfusion of blocked proximal veins and capillaries is slow, and there is no perfusion area in severe cases; (3) Blurred fluorescence of bleeding mass; ④ There was leakage in the distal vein and capillary, and the tissues in this area showed flaky strong fluorescence in the later stage; ⑤ Macular edema showed cystic strong fluorescence. Fluorescein angiography in the late stage of branch vein occlusion: ① capillary occlusion area is no perfusion area; ② collateral formation; ③ Microaneurysms appear at the edge of the occlusion area, which may lead to leakage; ④ Early leakage of new blood vessels; Macular cystoid edema presents petal-shaped fluorescent spots.
Fluorescein angiography of central vein occlusion showed: ① massive retinal hemorrhage blurred choroid and retina; ② No perfusion area and capillary no perfusion area appeared; ③ deep macular edema; (4) The vein wall is stained or slightly leaked; ⑤ leakage of new blood vessels and fluorescein; ⑥ Compensatory dilation of radial capillaries around the optic disc.
Electroretinogram: normal at the initial stage of onset. If the obstruction cannot be ruled out, the B wave in ERG will gradually decrease, forming a negative wave pattern. If the amplitude is smaller and smaller, the prognosis will be poor.
(3) treatment
1. Anticoagulant therapy should adopt coagulant such as heparin and dicoumarin in addition to the etiological treatment, and its function is to inhibit the formation of thrombin. Prothrombin time must be checked every day to prevent the risk of systemic bleeding. Fibrinolytic enzymes can also be used. āS meitou swollen leaning? Prisoner? What's the problem? Hella dental caries? Napp [13]? Hey? /P & gt；
2. Comprehensive treatment of traditional Chinese and western medicine can take vitamin C, rutin and vasodilators orally. At the same time, traditional Chinese medicine is given, which mainly clears away heat and cools blood in the early stage, and also has the effect of promoting blood circulation and removing blood stasis; In the middle stage, it mainly promotes blood circulation and removes blood stasis, and also has the effect of clearing away heat and improving eyesight; In the later stage, it can replenish liver and kidney, benefit qi and improve eyesight. The effect of drug therapy has yet to be evaluated.
3. Laser treatment of retinal vein occlusion Laser treatment has two purposes, one is to treat chronic cystoid macular edema, and the other is to destroy the capillary perfusion-free area and reduce the formation of new blood vessels.
4. Surgical treatment When venous embolism causes vitreous hemorrhage or net detachment, surgery must be performed.
Treatment principle: ① argon or krypton ion laser irradiation can be used for those who have not improved after drug treatment for more than four months. ② Low-energy laser is scattered evenly and sparsely in the anoxic region along both sides of the occluded branch. The laser spot size is 200u, and the spacing is about 1 laser spot, which is completed in 2 ~ 3 times in 2 weeks. ③ The photocoagulation point should avoid large blood vessels, macular area and optic disc spot bundle.