巩膜紫外光—核黄素交联术的有效性和安全性研究

发布时间：2018-06-15 20:26

本文选题：巩膜 + 胶原交联　；参考：《首都医科大学》2013年博士论文

【摘要】：目的：尽管近视的发生机制至今未明，但是研究普遍认为进行性近视的发生是由于各种先天和或后天的因素导致巩膜在眼内压的作用下变薄，进而造成眼球被动拉长引起的。巩膜的紫外光-核黄素胶原交联术是一项能增强巩膜自身生物力学强度的新技术。本研究旨在进一步评价目前国际研究中普遍采用的巩膜胶原交联方案在应用于新鲜尸眼和兔眼巩膜时的有效性和安全性。方法：本研究采用单向拉伸试验来评估该巩膜胶原交联方案增加生物力学强度的有效性。首先检测人眼巩膜紫外光-核黄素交联术的生物力学特性，将6只新鲜尸眼随机分为交联和非交联对照组，分别进行赤道部和后极部巩膜试件的应力-应变检测。接着，将20只新西兰兔随机分为4组，分别对非交联对照组、术后1周组、术后1月组和术后3月组的兔眼巩膜试件进行拉伸检测。在比较兔眼和人眼巩膜术后生物力学效果时，以应变为8%时的杨氏模量作为指标进行比较。在巩膜胶原交联安全性的研究中，本研究采用细胞脱氧核苷酸末端转移酶技术（Terminal deoxynucleotidyl transferase dUTP nick-end labeling，TUNEL）检测和电子显微镜技术（transmission electron microscopy，TEM）对6只新鲜尸眼赤道部巩膜进行检测评价，检验巩膜交联和未交联对人眼视网膜组织病理学的影响。随后，本研究对25只新西兰兔在巩膜交联术前、术后1周、1月和3月时的暗适应视网膜电图进行检测，并采用TUNEL染色和电子显微镜技术对兔眼视网膜组织病理学的影响进行观察和分析。结果：新鲜尸眼和兔眼巩膜的厚度在交联前后无统计学差别。兔眼和人眼巩膜的应力-应变曲线呈非线性变化，符合σ=Aexp(B*ε)指数方程。兔眼和尸眼的巩膜生物力学强度在交联后均得到增强。交联术后人眼赤道部巩膜杨氏模量是非交联赤道部巩膜的1.85倍，是交联术后人眼后极部巩膜杨氏模量的1.15倍；兔眼赤道部巩膜的杨氏模量在交联术后1周、1月和3月时分别增加到原来的297%,253%and163%；。经过巩膜交联的新鲜尸眼视网膜在TUNEL染色检测和电子显微镜检测中与非交联眼视网膜没有明显区别。交联术后1周和1月时兔眼暗适应ERG峰值有明显下降。尤其是Dark-adapted0.01ERG（1周，P=.001；1月，P=.022）和Dark-adapted3.0ERG（1周，P=.047；1月，，P=.035）的b波。而术后3月时的兔眼暗适应ERG峰值与术前没有统计学差异。交联术后1周和1月时兔眼视网膜中发现了大量的凋亡细胞。电子显微镜显示术后1周时兔眼视网膜的超微结构出现了异常。结论：实验证明，目前国际上普遍采用的巩膜交联研究方案能够明显增强兔眼和人眼巩膜的生物力学强度。然而，该巩膜交联方案可能并不安全，尤其是会引起兔眼视觉功能的慢性损伤，并可引起其视网膜细胞的凋亡。
[Abstract]:Objective: although the mechanism of myopia is still unknown, it is generally believed that the occurrence of progressive myopia is caused by various congenital and acquired factors, which result in sclera thinning under intraocular pressure, and then cause passive lengthening of the eyeball. Ultraviolet-riboflavin collagen crosslinking is a new technique to enhance the biomechanical strength of sclera. The purpose of this study was to evaluate the efficacy and safety of the scleral collagen crosslinking protocol which has been widely used in international studies in the sclera of fresh cadaver eyes and rabbit eyes. Methods: uniaxial tensile test was used to evaluate the effectiveness of the scleral collagen crosslinking regimen in increasing biomechanical strength. The biomechanical properties of scleral ultraviolet-riboflavin crosslinking were investigated. Six fresh eyes were randomly divided into cross-linked and non-cross-linked control groups. The stress-strain tests were performed in the equatorial and posterior polar scleral specimens respectively. Then, 20 New Zealand rabbits were randomly divided into 4 groups, and the scleral specimens of non-crosslinked control group, postoperative 1 week group, postoperative 1 month group and postoperative 3 months group were tested for stretching. The biomechanical effects of sclera surgery in rabbits and human eyes were compared with the Young's modulus at strain of 8. In the study of the safety of collagen crosslinking in sclera, terminal deoxynucleotidyl transferase dUTP nick-end labeling technique and transmission electron microscopy were used to detect and evaluate the equatorial sclera of 6 fresh cadavers. The effects of scleral crosslinking and uncrosslinking on the histopathology of human retina were examined. Subsequently, 25 New Zealand rabbits were examined for electroretinogram of dark adaptation before scleral crosslinking, 1 week, 1 month and 3 months postoperatively. The effects of Tunel staining and electron microscopy on the histopathology of rabbit retina were observed and analyzed. Results: there was no significant difference in scleral thickness between fresh cadaver eyes and rabbit eyes before and after crosslinking. The stress-strain curve of sclera of rabbit and human eyes showed nonlinear change, which was in accordance with 蟽 Aexpa B * 蔚) exponential equation. The scleral biomechanical strength of both rabbit and cadaveric eyes was enhanced after crosslinking. The Young's modulus of the equatorial sclera after crosslinking was 1.85 times of that of the non-crosslinked equatorial sclera and 1.15 times of that of the posterior pole sclera. The Young's modulus of the equatorial sclera of rabbit eyes increased to 29773 and 1633 at 1 week, 1 month and 3 months after crosslinking, respectively. The retina of fresh cadaveric eyes after scleral crosslinking was not significantly different from that of uncrosslinked eyes in Tunel staining and electron microscopy. At 1 week and 1 month after crosslinking, the peak value of ERG in rabbit eyes decreased significantly. In particular, the b waves of Dark-adapted0.01ERGG (1 week) and Dark-adapted3.0ERG (1 week) and January (P0. 035). However, there was no significant difference between the peak of ERG and the preoperative level of dark adaptation at 3 months after operation. A large number of apoptotic cells were found in the retina of rabbit eyes at 1 week and 1 month after crosslinking. The ultrastructure of the retina of rabbit eyes was abnormal 1 week after operation by electron microscope. Conclusion: the experimental results show that the scleral crosslinking research program widely used in the world can significantly enhance the biomechanical strength of sclera in rabbits and human eyes. However, the scleral crosslinking protocol may not be safe, especially can cause chronic damage of visual function and apoptosis of retinal cells in rabbit eyes.
【学位授予单位】：首都医科大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R779.6

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