动物造模,视网膜脱离动物模型 z-bio 2021-03-29 495

　　1 Combination of drug liquefaction and mechanical liquefaction

　　(1) There is no abnormality in the eye test of the copy method. A New Zealand rabbit weighing 2.0-2.5 kg was fixed and washed with 1% atropine eye drops to dilate pupils. One kilogram of anesthetic is anesthetized by injecting phenobarbital sodium intravenously into the edge of the ear. Open the eyelid with an opener, cut 4 mm behind the corneal ring, cut the eyeball conjunctiva into the sclera, and pierce the sclera with a 7 gauge needle. Under microscope and contact lens observation, guide the needle to the position of retinal detachment, make the needle as close as possible to the retina and avoid contact, and then inject 0.2 ml (3000 U) of hyaluronidase into the surface in a syringe. Extract 0.2 of the retina and local vitreous, then slowly inject it into milliliters and repeat 3-5 times. Finally, aspirate 0.3 ml of rapid impact on the retina, use rapid liquid to puncture the retina to form a hole in the retina, pull out the needle, suture the sclera and conjunctival incision, and sew erythromycin ointment. (2) The ophthalmoscope observation of the characteristic slit lamp of the model showed that the aqueous humor flickered and the vitreous body was slightly cloudy 1 to 3 days after the operation. After 3 days, the fundus became clear and the shape of the retinal laceration became rounded. Oval and volcano. Retinal detachment: 7 days after surgery, an average of 1.42 quadrants; 14 days after surgery, an average of 1.97 quadrants. Pathological examination confirmed the presence of retinal detachment.

　　(3) Comparative medicine The formation of retinal detachment must meet two conditions: glass liquefaction and the formation of retinal tear. When the liquefied vitreous body reaches the gap between the neuroepithelium and the pigment epithelium through a retinal laceration and separates the two layers of tissue, a retinal detachment is formed. The normal vitreous is in a hydrogel state, in which collagen fibers form a vitreous scaffold, and hyaluronic acid is attached to it. The closer the vitreous body is to the retina, the denser the structure of the vitreous stent. Therefore, even if there is a retinal tear, it is difficult for a normal vitreous body to enter under the retina through the tear and cannot form a retinal detachment. Therefore, the vitreous body must be liquefied to establish a retinal detachment model. In this model method, hyaluronidase is injected into the vitreous cavity to decompose the hyaluronidase in the vitreous stent. After the hyaluronidase in the vitreous stent is lost, the vitreous is repeatedly extracted with a syringe and the narrow cavity of the needle is used to destroy the collagen. The glass fiber stent completely liquefies the glass body in a short time. The rapid flow of fluid easily passes through the retina and creates holes in the retina. The shape of the hole in the retina is related to the direction of the impact needle. If the needle is perpendicular to the retina, the hole formed will form a crater or rupture. If the impact is small, it will be rounded up. Tilt the needle to form a circular or oval hole in the retina. Hole formation is related to local retinal detachment. This method can quickly and effectively establish a retinal detachment model, and is useful for clinical research on the etiology, influencing factors, treatment methods and prognosis of retinal detachment.

　　2 Mechanical injection method

　　(1) Copy method Choose a New Zealand rabbit weighing 2.0 to 2.5 kg, and intramuscularly inject 0.5 to 0.6 ml of shamisen for anesthesia. After regular disinfection, the surgical patch is fixed on the eye and an incision is made along the eye. Open the eyelid fissure and cut the conjunctiva along the limbs. The layered scleral suture was pulled 3 mm from the corneal annulus at 6:00 and 12:00, and 12 mm behind the corneal annulus at 6:00. Perform a 3mm puncture near the traction point at 12:00, and place a hole as a higher pressure site at 6:00. Use a 12-gauge flat injection needle to enter through the puncture hole. Using the ophthalmoscope under indirect vision, bring the needle close to the retina and remove 0.5 ml of the vitreous. Use a 50 mm glass microtube to pass the needle through the puncture hole, and under the direct vision of the indirect ophthalmoscope, use the glass microtube needle hole to lift the highest point (hole position) of the retina from the outside, and then the assistant injects 0.5 ml of saline. After confirming the swelling of the retinal spheroids, shake the glass microtube back and forth to appropriately expand the hole diameter to about 2 mm, and close the puncture hole with sutures.

　　(2) Model characteristics: This method will cause tears and retinal detachment, leading to some retinal detachment under the spinal cord, and the success rate is 100%. The disadvantage of this method is that the retention time of retinal detachment is inconsistent and the spontaneous reset is fast. (3) Establishing animal models of retinal detachment. Comparative medicine separates the retinal pigment epithelium from the neuroepithelium. Currently, there are many manufacturing methods, and different modeling methods inject different types of substances into the retina. There is a salt solution. , Blood, sodium hyaluronate and so on. Compared with other methods, this modeling method is easier and more convenient to combine the indirect ophthalmoscope with the highest pressure to identify the fracture hole model. This makes it easier to operate under direct viewing. In addition, the maximum pressure can be easily found, so as to ensure the consistency and standardization of the model surgery process and the replication effect.