【作者】 左绪宏；

【导师】 刘桂香；

【作者基本信息】 青岛大学 ， 眼科学， 2007， 硕士

【摘要】 目的：观察共同性外斜视病人内直肌超微结构及纤维连接蛋白变化，探讨共同性外斜视眼外肌病理组织学改变以及这些改变对共同性外斜视发生、发展的影响。材料和方法：1．共同性外斜视病人内直肌超微结构观察：选择共同性外斜视病人12例为外斜视组，同时选择无斜视等眼病的角膜移植供体内直肌7例作为对照组。从斜视矫正术中切除以及对照组内直肌标本取1mm~3的小块，置入3％戊二醛固定液中固定2天，1％锇酸后固定、逐级丙醇脱水后环氧树脂618包埋，半薄切片定位、超薄切片，甲苯胺蓝经醋酸铀及枸棒酸铝双重染色后，在JEM—1200EX型透射电镜下观察肌纤维及胶原纤维超微结构特点。比较外斜视组与正常组肌纤维中发生肌原纤维和线粒体病变例数差异，两组间胶原纤维平均直径、横切面积和密度的差异。2．内直肌纤维连接蛋白(FN)含量测定：选择共同性外斜视病人常规手术切除的内直肌段为外斜视组，共35例，再将其分成间歇性和恒定性外斜视2个亚组。另选20例角膜移植供体内直肌作为对照。免疫组化Sp法测量内直肌FN的表达，利用图像分析系统测定其平均光密度，将平均光密度作为免疫反应分值进行两样本间t检验。统计分析FN表达在外斜视组与正常组、间歇性和恒定性外斜视两亚组间、不同性别间、阴阳性家族史病人间的差异，以及与斜视度、病人年龄之相关性。结果：1．超微结构改变：①外斜视组内直肌肌纤维超微结构的变化主要表现为肌原纤维排列紊乱、稀疏甚至溶解消失以及肌小节z带不清或者消失；线粒体增多、增大、空泡化。发生的肌原纤维损害在外斜视组中有10例而对照组中仅2例，两者有显著性差异(P=0.0449)；线粒体的异常外斜视组中有11例而对照组中2例，两者差异具有极显著性P=0.0095)。②胶原纤维的变化。胶原纤维在所有内直肌中排列不规则形成三维结构，横切面为规整的圆形。外斜视组胶原纤维的平均直径54.23±6.86nm，对照组46.96±4.97nm；横切面积2394.43±624.44nm~2，对照组1764.62±368.77nm~2；面积标准差斜视组651.46±301.13，对照组330.99±45.55，统计学处理3者之间均有显著性差异(P值分别为0.0257、0.0272、＜0.0500)。而斜视组密度(180.83±58.20／10~6nm~2)与对照组(198.57±63.27／10~6nm~2)比较差别无显著性(P=0.5427)。2．内直肌FN表达结果：外斜视组的内直肌FN表达量(0.5228±0.0991)明显低于正常组(0.5914±0.0547)，差异有极显著性(P=0.0062)。间歇性外斜视亚组FN表达量(0.5821±0.0792)明显高于恒定性外斜视亚组(0.4729±0.0872)，差异有极显著性(P=0.0005)。而FN在病人不同性别、有无家族史病人之间差异无显著性(P＞0.05)，与病人年龄以及斜视度数也无关。结论：1．肌纤维的损害及线粒体的异常表明共同性外斜视病人内直肌肌纤维有组织病理学改变，导致内直肌收缩功能的下降，可能与产生外斜视的生物力学相关。2．胶原纤维直径增大、变粗等异质性改变，以及纤维连接蛋白表达的降低，提示内直肌力的应力及力的传导异常，细胞外基质异常可能是共同性外斜视的发生的重要因素。3．眼外肌纤维本身和细胞外基质成分的变化，可能在共同性外斜视的发生发展中的扮演着重要角色，今后应重视它们的研究。更多还原

【Abstract】 PurposeTo study on the changes of ultrastructure and fibronectin in the resected medialrectus muscles in patients with concomitant exotropia, and to have a betterunderstanding about the pathomorpholosical changes of extraocular muscles in thegenesis and development of concomitant exotropia.Materials and methodsTwelve concomitant exotropic patients were chosen as exotropic group and 7normals were selected as control group that were selected from cornea donatorsexcluded strabismus. All the resected tissues of the medial rectus muscles wereobtained from patients with concomitant exotropia during resection surgery andcornea donators. They all were cut into 1 mm~3 pieces,fixed in 3％glutaraldehyde,bufferred, postfixed 4 hours with 1％osmium tetroxide, bufferred, dehydratedgradually in ethyl carbinol, embed in ethoxyline 618. After semithin sectionlocalization, ultrathin-secti stages, stained with toluidine blue uranyl acetate andmedlar clavulanic acid alum,the sections were observed on JEM—1200EXtransmission electron microscope. Statistical comparison was performed on the casenumber that has pathological changes of muscle fiber such as myofibril andmitochondria, and the mean diameter, transverse area and density of collagen fibrilsbetween the control group and the exotropic group.Thirty-five concomitant exotropic patients were chosen as exotropic group and21 normals which were selected from cornea donators were selected as control groupExotropic patients were divided into intermittent s and constant exotropic groups. Allthe resected tissues of the medial rectus muscles were fixed 48 hours,embedded inparaffine and sliced to 3 micron,and then carried out immunohistochemistry study(sp).Fibronectin were measured its mean average Optical Density Value usingimage analyzer. The amounts of fibronectin of resected muscle of patients werecompared with normals, as well as correlated clinical data of patients such as differenttypes of exotropia, age, degree of deviation,gender and positive family history.Results On electron microscopy, various changes are found in both groups. Theseinclude①muscle fiber, myofibrils damages such as arrange disorderly sparse evendissolves, as well as the z belt is unclear or vanishes, presented in 10 cases ofexotropic group while 2 case of control group (P=0.0449). Mitochondriaabnormities, such as vacuole, increment or growing in quantity, presented in 11 casesof exotropic group while 2 case of control group (P=0.0095).②collagen fibrils,groups of collagen fibrils arranged irregularly in different orientations, forming athree-dimensional network in the rectus outside the muscle fibrils in both groups. Allfibrils had a round, regular contour. In the exotropic group, the collagen fibrils werethicker, as reflected by their significantly greater mean diameter: 54.23±6.865nm(mean±standard deviation) compared to 46.96±4.97nm in the control group.Also, significantly greater heterogeneity was found in the collagen fibril thickness ofeach individual in the exotropic group compared to the control group (Mean fibrilarea, nm~2) of the individual of the exotropic and control group were 2394.43±624.44and 1764.62±368.77 respectively(P=0.0272). Within-individual standard deviation offibril area was 651.46±301.13 and 330.99±45.55 respectively (P＜0.0500). However,the mean density of collagen fibrils in the exotropic group was 180.83±58.20 fibrilsper 106 nm~2 compared to 198.57±63.27 fibrils per 106 nm~2 in the control group,which has no statistic significance (P=0.5427).The amounts of fibronectin in the resected medial rectus muscles of patientswith concomitant exotropia (0.5228±0.0991) were significantly lower than those ofnormals (0.5914±0.0547) (P=0.0062). Patients with intermittent exotropia(0.5821±0.0792) showed significantly larger amounts of fibronectin than those withconstant exotropia (0.4729±0.0872) (P=0.0005), while the amounts of fibronectinhad no correction with age and degree of deviation. Neither gender nor positive familywas correlated with the amounts of fibronectin (P＞0.05).Conclusion1. Myofibrillar damage and mitochondrial abnormality suggest that EOMs fromindividuals with concomitant exotropia possess unique structural characteristicssuggestive of relationship with biomechanics that induces this diseases.2. Greater mean diameter of collagen fibrils, heterogeneity in the collagen fibril thickness of each individual and the lower amount of fibronectin in the exotropicgroup may shown abnormal mechanical stress and force conduction. Extracellularmatrix play an important role in the pathogenesis of concomitant exotropia.3. The pathomorpholosical changes of extraocular muscles may be importantfactors in the development of concomitant exotropia, which further research is neededto determine more definitely on.更多还原