高强度聚焦超声应用于兔眼角膜矫正老视的初步研究

发布时间：2018-06-02 01:06

本文选题：老视 + 高强度聚焦超声　；参考：《重庆医科大学》2012年硕士论文

【摘要】：目的：利用高强度聚焦超声(HighIntensityFocusedUltrasound，HIFU)定位辐照新鲜离体兔眼角膜基质，在HIFU不同的辐照功率下，分别制作不同直径的圆环状焦域，观察HIFU对新鲜离体兔眼角膜组织形态、角膜曲率半径和曲率的影响，探讨HIFU应用于兔眼角膜矫正老视的安全性与有效性，建立HIFU辐照新鲜离体兔眼角膜基质的适宜参数，为HIFU矫正老视提供基础实验数据。方法：HIFU辐照离体兔眼角膜动物模型的构建；实验选用新鲜离体兔眼，分为对照组和实验组，对照组兔眼未行任何实验处理做正常空白对照，实验组：HIFU在相同的治疗时间(6s)下，以1w、2w、3w、4w不同功率定位辐照兔眼角膜基质，分别制作不同直径（8mm，9mm，10mm）的圆环状焦域，大体观察角膜焦域情况，HE染色光镜下观察角膜基质焦域情况，Digimizer软件测量焦域的最大长径和最大宽径，电镜下观察对照组、1w/9mm组和3w/9mm组角膜焦域内基质细胞及纤维改变情况，自动验光仪及角膜地形图检测辐照前后1w/9mm组和3w/9mm组兔眼角膜的曲率半径和曲率。结果:1.成功构建HIFU辐照离体兔眼角膜的动物模型。2.HIFU定位辐照角膜基质，不同辐照功率在角膜上可分别制作不同直径（8mm，，9mm，10mm）的圆环状焦域，大体观察可见辐照处角膜呈灰白色、边界清楚，辐照处角膜上皮无损伤。3.经HIFU辐照后，光镜下可见角膜基质内焦域呈椭圆形、颜色加深、边界清楚，基质内HIFU辐照处板层纤维排列规则、纤维之间出现融合，辐照处边界纤维呈现收缩状态，2w/8mm组、3w/8mm组、3w/9mm、3w/10mm组、4w/8mm组、4w/9mm和4w/10mm组角膜焦域内融合纤维之间的间隔减小、焦域边界纤维收缩明显，焦域内基质细胞体积与未辐照区基质细胞体积相比明显减小。焦域环直径相同时、焦域的最大长径与宽径随辐照功率的增大而增大，各实验组比较差异有统计学意义(P0.05)；辐照功率相同时、焦域的最大长径随焦域环直径的增大而减小，各实验组比较差异有统计学意义(P0.05)。4.电镜结果表明1w/9mm组角膜基质焦域内细胞超微结构正常、纤维轻度弯曲，而3w/9mm组焦域内细胞出现线粒体和细胞质的溶解、纤维之间扭曲交错明显。5.自动验光仪检测结果显示：HIFU辐照角膜基质后兔眼角膜曲率半径减小、曲率增加，辐照前后差异有统计学意义(P0.05)；在焦域环直径相同的情况下，随HIFU辐照功率的增大，兔眼角膜曲率半径减小及曲率增加更明显，差异有统计学意义(P0.05)。角膜地形图检测结果表明：无论HIFU辐照功率高低，HIFU辐照后均可引起角膜曲率的增加。结论：1.HIFU可精确定位于角膜基质层内，辐照处与未辐照处有着明确分界线，HIFU对辐照区外邻近正常组织无明显影响，表明HIFU在兔眼角膜上进行无创矫正老视的探索模式具有损伤少、定位精确的特点，提示HIFU应用于兔眼角膜无创矫正老视具有巨大应用前景。2.本实验认为1w/8mm组、1w/9mm组、1w/10mm组、2w/9mm组和2w/10mm组形成的角膜基质内焦域大小适宜，焦域内仅纤维出现收缩改变、未见细胞损害，适合辐照离体兔眼角膜基质用于老视矫正模型，从组织形态学观察结果来看，其具有较高的安全性，为HIFU矫正老视的后续研究提供了实验基础与依据。3.HIFU热效应能使兔眼角膜基质胶原纤维收缩，产生角膜前凸效应，兔眼角膜曲率半径减小、曲率增加，且随辐照功率的增大角膜曲率增加更明显，HIFU有望成为一种有效矫正老视的新方法。
[Abstract]:Objective: to locate the corneal stroma in fresh rabbit eyes by HighIntensityFocusedUltrasound (HIFU), and to make the circular focal region of different diameter at different radiation power of HIFU, and observe the effect of HIFU on the corneal morphology, radius of curvature and curvature of cornea in fresh rabbit eyes, and discuss the application of HIFU to the cornea of fresh rabbit eyes. To correct the safety and effectiveness of the cornea of rabbit's cornea, the appropriate parameters of HIFU irradiated corneal stroma in fresh rabbit eyes were set up to provide basic experimental data for HIFU correction of old vision.
Methods: HIFU irradiated rabbit corneal animal models were constructed. The experimental rabbits were divided into the control group and the experimental group, the control group was divided into the control group and the experimental group. The control group was not treated with any experimental treatment to do normal blank control. The experimental group: under the same treatment time (6S), the rabbit cornea matrix was irradiated with 1W, 2W, 3W, 4W, and the rabbit cornea matrix was irradiated with 1W, 2W, 3W and 4W, respectively. The circular focal region of different diameters (8mm, 9mm, 10mm) was used to observe the focal region of the cornea. The focal region of the corneal stroma was observed under the HE staining light microscope. The maximum diameter and maximum width of the focal region were measured by the Digimizer software. The changes of matrix cells and fiber in the corneal focal area of the 1w/9mm and 3w/9mm groups were observed under the electron microscope. The automatic optometry and angle were observed. The curvature radius and curvature of cornea in group 1w/9mm and 3w/9mm before and after irradiation were detected by membrane topography.
Results: 1. the animal model of cornea of HIFU irradiated rabbit cornea was successfully constructed by.2.HIFU location irradiated corneal stroma. Different radiation power could be used to produce circular focal region of different diameter (8mm, 9mm, 10mm) on the cornea. The cornea was gray white, the boundary was clear, and the cornea epithelium was irradiated without damage of.3. after irradiation by HIFU. Under the microscope, the focal area of the corneal stroma was oval, the color deepened, the boundary was clear, the lamellar fibers arranged at the HIFU irradiation in the matrix, the fiber appeared to be fused, the boundary fibers in the radiation were contracted, the 2w/8mm, 3w/8mm, 3w/9mm, 3w/10mm, 4w/8mm, and the focal area of the corneal focal region of 4w/9mm and 4w/10mm were reduced. At the same time, the maximum diameter and width of the focal region increase with the increase of the radiation power, and the difference of the experimental groups is statistically significant (P0.05). The maximum diameter of the focal region with the same radiation power is with the maximum diameter of the focal region. The diameter of the focal region was reduced, and the difference between the experimental groups was statistically significant (P0.05). The results of.4. electron microscopy showed that the cells in the focal area of the corneal stroma of the 1w/9mm group were normal and the fibers were slightly curved, while the cells in the 3w/9mm group were dissolved in the mitochondria and cytoplasm, and the twisted interlaced.5. automatic optometrer detection junction between the fibers was observed. The results showed that the radius of curvature of cornea was reduced and the curvature of cornea increased after HIFU irradiated corneal stroma, and the difference was statistically significant (P0.05) before and after irradiation. With the same diameter of the focal region, the corneal curvature radius and curvature increased with the increase of HIFU radiation power, and the difference was statistically significant (P0.05). The results showed that no matter the HIFU irradiation power, the corneal curvature could be increased after HIFU irradiation.
Conclusion: 1.HIFU can be accurately located in the corneal stroma layer, and there is a clear dividing line between the irradiated and unirradiated areas. HIFU has no obvious influence on the adjacent normal tissues outside the irradiated area. It shows that the exploration mode of HIFU in the cornea of rabbit's cornea is characterized by little damage and accurate positioning, suggesting that HIFU is applied to the corneal noninvasive correction of rabbit's cornea. Presbyopia has great potential application prospect.2. this experiment thinks that the focal area of corneal stroma formed in group 1w/8mm, group 1w/9mm, 1w/10mm, 2w/9mm and 2w/10mm is suitable for the size of focal area in the corneal stroma, the only fiber in the focal region is changed and no cell damage is found. It is suitable to irradiate the cornea matrix of the rabbit eye in vitro for the old visual correction model. It has high safety. It provides experimental basis for the follow-up study of HIFU correction presbyopia and the thermal effect of.3.HIFU can make the cornea matrix collagen fibers contract and produce the corneal lordosis effect. The radius of curvature of cornea of rabbit's eyes decreases, the curvature of cornea is increased, and the increase of corneal curvature is more obvious with the increase of radiation power. HIFU is expected to become a kind. A new way to correct presbyopia.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R772.2

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