【作者】 向一旻；

【导师】 杜之渝；

【作者基本信息】 重庆医科大学 ， 眼科学， 2008， 硕士

【摘要】 目的:观察比较Flap-free Epi-LASIK和Epi-LASIK两种术式术后角膜上皮下雾状混浊(Haze)的发生发展情况并初步探讨其机理。方法:健康新西兰大耳白兔21只,其中18只兔一眼行Flap-free Epi-LASIK另一眼行Epi-LASIK,用VISX20/20准分子激光仪作-10D切削,另3只兔作为空白对照。各组分别于术后1月、2月、3月共3个时间点定期在裂隙灯下进行Haze分级评估。随机选取各组动物6只眼,取角膜组织后三等分:一半切片用于组织学检测,另一半冻存用于分子生物学检测。第一部分:取角膜组织利用透射电镜、逆转录聚合酶链反应(reverse transcription-polymerase chain reaction, RT-PCR)和免疫组织化学(immunohistochemistry,IHC)等方法观察Haze相关指标。第二部分:用免疫组织化学方法检测转化生长因子(TGF-β2)和碱性成纤维细胞因子(b-FGF)的表达水平,比较和探讨其在两种术式术后Haze形成及发展过程中的作用。结果:术后各时间点,Haze分级水平与α-平滑肌动蛋白(α-SMA)及Ⅲ型胶原mRNA表达结果显示Flap-free Epi-LASIK和Epi-LASIK术后各时间点的组间差异均无统计学意义(P>0.05)。透射电镜检测结果发现,各组不同时间点上皮层结构及基底膜基本完整,1月及3月两实验组基质细胞均较正常,胶原排列比较整齐;2月两实验组基质细胞明显活跃,胶原排列紊乱。RT-PCR检测显示:术后各时间点Epi-LASIK组和Flap-free Epi-LASIK组Ⅲ型胶原mRNA的表达差异均无统计学意义;术后Ⅲ型胶原纤维mRNA的组内动态表达呈现出先升高后降低的特点,均在术后2月时达高峰。免疫组化检测显示:术后各时间点Epi-LASIK组和Flap-free Epi-LASIK组TGF-β2、b-FGF的表达差异无统计学意义(P>0.05);TGF-β2的表达水平组内比较呈逐渐下降的特点;b-FGF的表达水平在两实验组差异均无统计学意义(P>0.05),且均随时间延长呈持续升高的趋势。结论:兔Flap-free Epi-LASIK和Epi-LASIK术后Haze形成及发展程度相似;两种术式术后影响Haze形成及发展的关键调控因子TGF-β2和b-FGF表达无明显差异。更多还原

【Abstract】 Objective: Observe and compare the cornea epidermis haze develop-ment after Epi-LASIK and Flap-free Epi-LASIK operation, and preliminary probe into its pathogenesis.Methods: 21 heathy New Zealand big-eared rabbits, 18 of them are performed Flap-free Epi-LASIK and Epi-LASIK operation respectively on each eye. Then do -10D cutting with VISX20/20 . The other 3 rabbits are use to be reference. Classify and evaluate the haze formed of each group under slit lampapartly one month, two months and three months later of the two operations. Select 6 eyes from each group at random. Then take their corneal tissue and halve them. One half is used to histology examination and the another half is freezed and used to biology examination. The first part: Take the corneal tissue and make use of TEM , RT-PCR and IHC etc. to observe the correlative index. The second part: Use IHC method to ex-amine expression of TGF-βand b-FGF.Compare and probe into its function during the haze forming and developing after the two kinds of operations.Results: At each time point Haze’s classification, expression ofα-SMA and collagen typeⅢmRNA show that there is no statistics meaning of in-terclass discrepancy after Flap-free Epi-LASIK and Epi-LASIK operation. TEM reuslt shows that epithelium tissue and basement membrane are almost intact at each time point. stroma cell in the first and third month are normal and collagen arranges orderly; In the second month, stroma cel are active obviously but collagen arranges disorderly.RT-PCR examine shows that there is no obvious statistics discrepancy of expression of collagen typeⅢmRNA after the two operation, Epi-LASIK and Flap-free Epi-LASIK at each time point; development expression of collagen typeⅢmRNA presents rising first and falling later, and reaching its height two month later of operation. IHC examine shows that there is no obvious statistics discrepancy of expression of TGF-β2、b-FGF after the two operation, Epi-LASIK and Flap-free Epi-LASIK at each time point; expression of TGF-β2 presents falling gradually; But expression of b-FGF presents rising gradually with time prolonging.Conclusion: The haze forms and develops similarly after two kinds of operation to rabbit, Epi-LASIK and Flap-free Epi-LASIK. There is no bo-vious discrepancy of the key factor TGF-β2 and b-FGF’s expression which affect Haze’s forming and development after operations.更多还原