动物造模,低眼压动物模型 z-bio 2021-03-29 692

　　1 Low intraocular pressure model induced by ciliary body

　　(1) After the replication test, 0.15 ml/kg of compound Smianxin injection was injected intramuscularly into a blue-purple blue rabbit. The rabbit has normal eyes and weighs about 2 kg. .. The weight of general anesthesia is then used to measure intraocular pressure with Schauer tonometer. The right eye of the operation was given compound troptropamide eye drops every 3 minutes for a total of 3 times. Then proceed to Cyclocryotherapy (Cyclocryotherapy, CCT). The diameter of the condenser head is 22 mm, the front edge is located in the corneal ring, the upper half is 180°, the average coagulation is 6 points, and the coagulation condition is -80°C, 60 seconds.

　　(2) Model characteristics The intraocular pressure of the animal decreased 5 days after the operation, and then gradually increased. Compared with the basal intraocular pressure 3 weeks after the operation, the intraocular pressure of the model animal decreased slightly. , The intraocular pressure of albino rabbits is lower than the basal intraocular pressure. B is not as good as paint. The intraocular pressure of rabbits is significantly reduced, and pathological damage to cilia can be seen through micro-histopathological observation. .. Ciliary body coagulation is easy to operate, but the postoperative inflammation is severe, the degree of intraocular pressure drop is unpredictable, and the surrounding tissues are damaged. Postoperative complications include inflammation of the iris ring, limbal angiogenesis, anterior eye ischemia, and eye atrophy.

　　(3) Comparative medicine. Low intraocular pressure is a long-term, common pathological process during which most eye diseases will become blindness and atrophy. When low intraocular pressure occurs, clinically ineffective measures can be taken to control it. In the field of intraocular pressure research, low intraocular pressure is relatively ignored. At present, the pathological changes of the eye under low intraocular pressure are not very clear, and it is necessary to establish a hypotonic animal model for corresponding research. Methods of establishing low intraocular pressure models include ciliary body destruction, ciliary body separation or choroidal detachment, establishment of ciliary body, induction of inflammation, and models of proliferative vitreoretinopathy, including establishment and so on. Intraocular pressure can be reduced to varying degrees. However, they have their own shortcomings and need further study. The establishment of an ideal hypotension animal model can provide experimental evidence for the study of its pathophysiological changes, clinical treatment and prevention. Pigmented rabbits are more susceptible to damage than albino rabbits. This phenomenon is called "hyperpigmentation effect." Pigmented cats will produce ciliary condensation. The wider the degree of condensation, the more obvious the effect of lowering blood pressure. . Akagesaru's ciliary condensation in both eyes, optical and electron microscopic changes of the hyperemia nipple under low intraocular pressure, postoperative intraocular pressure temporarily increased, after 3 months, most of the eyeballs became soft and the intraocular pressure could not be measured. The cat’s ciliary body extends 4 mm behind the corneal ring, which is easier to locate than rabbits and provides a stable blood and water barrier. This method is suitable for establishing a low intraocular pressure model. The eye structure of primates is similar to that of human eyes, and the models created are more valuable for reference, but due to ethical and price factors, research is limited.

　　2Proliferative retinopathy (PVR) induced chronic hypotension model after trauma

　　(1) After the replication method test, press normal eyes and a blue-purple blue rabbit weighing about 2 kg and weighing 0.15 ml/kg. The compound Sanweixin injection was anesthetized for general anesthesia, and the intraocular pressure was measured with a Shu's tonometer. After dropping the compound tropinamide into the experimental eyes 3 times every 3 minutes, they were disinfected with ethanol, the towels were spread out, the eyelids were opened, and the anterior chamber was punctured with a sharp knife along the upper corneal ring at 11 o'clock. , Use the fourth needle to create the cystectomy needle. The eye is perfused with balanced salt from the puncture opening to the anterior chamber, and the nucleus is separated from the water after the sac is cut. The ring incision is enlarged to 8-9 mm. The lens nucleus and part of the cortex are released. The iris and ciliary body were cut radially at 11 o'clock and 5 o'clock. The blood vessels at the root of the iris bleed spontaneously. Repeated use of the cystectomy needle to tear and penetrate the capsule. Stir the vitreous body near the ciliary body to mix bleeding, torn capsular membranes, and the remaining small amount of lens cortex. Remove the prolapsed vitreous body and suture the ring incision. Inject balanced ocular salt into the anterior chamber to restore the anterior chamber and intraocular pressure to normal levels. There is no leakage from the incision. The subconjunctival injection of gentamicin is 20,000-40,000 u, and atropine ointment is used for the conjunctival sac. The anterior part of the control eye was the same as the experimental eye, but after delivery of the lens nucleus and all cortex, no other treatment was performed. The limb incision was sutured and the intraocular pressure was restored. The operation is the same. Experiment with eyes. One day after surgery, 1, 2, 4, and 8 weeks, after general anesthesia, the same anesthetic was injected intramuscularly, the intraocular pressure was measured with a Shaw tonometer, and the rabbits were treated with 1 and 2. After anesthesia for 4 to 8 weeks after the operation, the eyeballs were collected to prepare conventional histopathological sections and observed with an optical microscope.

　　(2) Model features When pathological observation of model animals was performed with a ciliary body microscope, the ciliary bodies of the experimental and control eyes were swollen and fibrous on the surface 1 and 2 weeks after the operation. Have seen. Ciliary process However, the experimental eye is more exudative, has a small number of inflammatory cells, and the ciliary epithelium is basically normal. Two weeks after the operation, the swelling of the ciliary body of the experimental and control eyes decreased. Within a week. Four weeks after the operation, the ciliary body of the experimental eye was still slightly swollen, but the ciliary body of the control eye had basically subsided. There are proliferating fiber bundles on the surface of the ciliary process of the experimental eye, and a single inflammatory cell is still visible. The epithelium was basically intact, but the ciliary process surface of the control eye did not grow. Eight weeks after the operation, the ciliary body swelling of the experimental and control eyes basically disappeared, but more fiber bundles grew on the surface of the ciliary process of the experimental eye, and the ciliary epithelium was disordered in many areas of the body. , And some areas of the epithelium show atrophy and atrophy. The epithelial structure disappeared. There are separate fiber cords on the surface of the ciliary process of the control eye, but the ciliary epithelium is intact. This model is ideal for the formation of chronic low intraocular pressure and is relatively close to actual trauma.

　　(3) Comparative medicine Chronic low intraocular pressure is one of the most serious complications after human eye trauma. Usually, the visual function of the injured eye is weakened or even more serious, leading to eye atrophy. Clinically, there are many reasons for chronic intraocular hypotension after trauma. With the extensive development of vitreous and retinal surgery, the role of anterior PVR in chronic post-traumatic hypotension has been widely recognized. After eye trauma, surgery can successfully reposition part of the retina of the eye, but after surgery, the intraocular pressure is lower than normal for a long time, which may cause the reattached retina to detach or damage vision, which may be feasible. . Since chronic post-traumatic hypotension is usually related to pre-traumatic PVR, it is very important that we will study the mechanism and treatment of chronic hypotension caused by pre-traumatic PVR. .. At present, through the establishment of corresponding animal models of chronic low intraocular pressure, experimental studies of chronic low intraocular pressure caused by pre-traumatic PVR are gradually carried out. This experiment involves other methods of creating a low intraocular pressure model. From a trauma point of view, the use of PVR before post-traumatic causes long-term low intraocular pressure in animals. The results of this model are relatively close to actual trauma, so it is used as a pre-traumatic PVR that causes chronic low intraocular pressure. The mechanism and clinical treatment of intraocular pressure have been well studied in animal models. In the process of creating this model, care should be taken to create the model from the perspective of trauma rather than from the perspective of surgery. If you create it from the perspective of surgery, you will not get the desired effect. From the perspective of surgery, we pay attention to the principles of sterility, mild surgery and avoiding bleeding, but this will not promote the development of inflammation or the appearance of fibrosis. When creating the model, please be careful not to completely aspirate the lens cortex after the lens nucleus is delivered. Only a small part of the ruptured cortex remains, because it has a positive effect on inflammation, so you need to be careful. The iris and ciliary body are cut radially from 11:00 and 5:00, reaching the bottom of the iris. This ensures that the arterial ring of the iris is severed, causing bleeding and dilation after the operation to prevent later occurrence. -Causes surgical inflammation and dizziness, causes pupil obstruction and affects aqueous circulation. Before suturing the incision, mix the iris and vitreous behind the ciliary body, bleeding and ruptured capsules with the remaining small amount of lens cortex to produce a relatively strong inflammatory response. If you do not want retinal detachment, you need to move the capsular bag incision needle. Move forward to avoid retinal detachment caused by posterior diffusion. Cut open the escaping vitreous body until it cannot escape spontaneously, remove the anterior chamber vitreous body, and avoid obstruction of the pupil. After cutting off the large ring of the iris artery, if there is no bleeding, you can remove some ciliary processes from 11 o'clock to allow blood to flow into the eye naturally. After suture the incision, restore the anterior chamber and intraocular pressure. If the balance salt is insufficient, gas can be used to prevent the iris and ciliary body from adhering to the cornea and blocking the angle of the chamber. At the same time, the rabbit lens is relatively large, so you need to set up controls. Simply removing the lens will significantly reduce the intraocular pressure of the rabbit and eventually return to normal levels.