动物造模,药效评价,近视眼 z-bio 2024-07-31 714

　　The modeling mechanism uses various methods to focus the object image behind the retina, causing the eyeball to be in a farsighted optical defocus state. By regulating mechanisms (sclera, choroidal pathway) to control changes in the ocular axis, compensatory growth of the ocular axis is achieved. The eyeball stops growing only when the axial length reaches the defocused focal point. Some people believe that this model utilizes the scleral mechanism to accelerate the growth of the eyeball sclera and the reconstruction of the posterior pole, while the choroidal mechanism causes the choroid to become thinner and the retina to shift backward, resulting in myopia. When the object image becomes clear, the process of emmetropization stops the elongation of the eyeball axis.

　　[Method of Modeling]

　　1. The spherical defocusing method fixes the concave lens in front of the animal's eyes, and can choose to use eye masks, face shields, surgical suturing lenses, or laser surgery to cause defocusing of experimental animals. Animals should be raised under normal light and fed according to the circadian rhythm. Wearing glasses of -10.00D on mice that have just opened their eyelids resulted in axial myopia of -13.00D around 6 weeks. After wearing defocus lenses on newly opened guinea pigs, the degree of myopia induced varies depending on the degree of the lens worn. Within -8.00D, the increase in axial length is linearly positively correlated with the degree of the lens, but some scholars believe that at least -6.00D or more lenses are required to induce myopia in guinea pigs.

　　2. Corneal astigmatism can also cause defocusing of objects and form blurry images, with a certain degree of visual detachment effect. Fix the astigmatism lens with a diameter of at least 2.00D in front of the eyes of the newly opened experimental animal, or use surgical methods to induce high astigmatism in the cornea of the experimental animal. After about 2 weeks, the eye axis will become longer.

　　3. The method of limiting the visual distance of experimental animals is used to simulate acquired myopia in adolescents. Keeping young experimental animals in small places or forcing them to look up close can cause the formation of myopia. Raising young chickens in a narrow flower cloth covered experimental cage with a visual distance limit of 5-10cm, forcing them to select food from the sand, and developing varying degrees of myopia after 15 weeks of feeding. Fixing young monkeys in a position of looking up close (such as on the floor) or using a hood to limit their line of sight for several hours a day for several months to one year can induce a model of myopia in monkeys.

　　[Model Features] It can cause different degrees of myopia models, and the defocus lenses used in this model are roughly divided into: ① high defocus lenses (>-10.00D); ② Gradient defocusing lens (-2.00~10.00D, with 2D gradient). Research shows that a defocusing lens of at least -6.00D is required to induce significant myopia after complete correction of refractive errors.

　　[Model Evaluation and Application] The main advantage of this model is that the spherical defocus method can select and control the defocus degree to control the myopia degree of experimental animals, which is the main advantage of this model; Secondly, the method of limiting line of sight simulates the pathogenesis of acquired myopia in adolescents due to extensive close range learning and work, which is also its unique feature. However, when using this model, scholars often use the method of comparing the contralateral eye with the wearing of lenses on one eye. However, this often results in anisometropia, and the occurrence of monocular suppression does not meet expectations; At the same time, the defocusing of highly concave lenses beyond the animal's visual range is not in line with our expectation of using adjustment that leads to adjustment fatigue. The choice of defocus lens power is related to the degree of myopia produced, with guinea pigs being more sensitive to low defocus. Applicable to the study of the pathogenesis of myopia.