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1.
目的对海德堡视网膜断层扫描仪(HRT)黄斑水肿分析软件(MEM)进行黄斑厚度测量的可重复性评价。方法对62名正常人(9~68岁)用HRT-Ⅱ黄斑程序进行检查,对黄斑部视网膜信号宽度、中心凹视网膜信号宽度和黄斑水肿指数进行均数分析、t 检验和相关分析,对个体内重复测量的变异性采用变异系数、95%耐受限(TC)、类内相关系数(ICC)进行研究。结果正常人的黄斑部视网膜信号宽度为(0.734±0.236) mm,中心凹视网膜信号宽度为(0.781±0.243)mm,平均水肿指数E=(1.169±0.619)。各参数的重复测量变异系数分别为:视网膜信号宽度(8.7±6.8)%,中心凹视网膜信号宽度(8.5±6.7)%, 平均水肿指数(15.6±13.9)%;个体内连续重复测量发生改变的95%TC分别为,视网膜信号宽度0.131(8.9%);中心凹信号宽度0.137(10.5%);平均水肿指数0.198(7.4%)。同一操作者对同一个体进行多次重复测量的ICC分别为:黄斑区视网膜信号宽度0.950;中心凹信号宽度0.949;平均水肿指数0.898。结论海德堡视网膜断层扫描仪MEM软件,具有无创、快速、可重复性较好等特点,为视网膜厚度相关的黄斑疾病的客观定量监测提供了一种新的手段。(中华眼底病杂志,2005,21:103-105)  相似文献   
2.
目的 探讨不同瞳孔直径下,调节对年轻正视眼单色高阶波阵面像差的影响.方法 干预性试验研究设计.使用光线追踪原理的波阵面像差仪测量12只年轻正视眼自然生理状态,在4.0、3.0、2.0 mm瞳孔直径下,0.00、1.00、2.00、3.00和4.00 D调节刺激下的单色波阵面像差.采用单因素方差分析及最小显著差法多重比较,对获得的数据进行统计学分析.结果 调节松弛下正视眼的总高阶像差、总彗差、总高阶散光、总球差和总三叶草像差的均方根值均随瞳孔直径减小而减小.在4.0、3.0、2.0mm瞳孔直径下,总彗差是调节松弛状态总高阶像差的最主要成分;总高阶像差仅在调节刺激达4.00 D时升高(P<0.05).瞳孔直径4.0 mm时,随调节刺激增加,4阶球差出现从大到小、从正值向负值的变化,但在瞳孔直径为3.0和2.0 mm时,4阶球差始终为正值.3阶水平方向三叶草像差在4.0、3.0、2.0 mm瞳孔直径下均表现出从负值向正值变化的规律.结论 不同瞳孔直径不同调节刺激下,正视眼各项单色高阶波阵面像差发生了不同规律和方向的变化.高阶像差在调节过程变化的意义和对不同注视距离视觉处理过程的作用有待于进一步研究,波阵面像差的研究将从单纯的消除向优化方向发展.  相似文献   
3.
目的 探讨皮质下脑卒中后手运动相关脑区正负网络连接的变化及与运动功能障碍的关系.材料与方法 对18例单侧皮层下脑卒中患者和18名性别、年龄完全匹配的健康志愿者分别进行静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)检查.以左侧初级运动皮质(primary motor cortex,M1,对应病灶侧)内与手运动功能相关的区域为感兴趣区,基于体素水平的全脑功能连接方法 分析手运动相关的正网络和负网络;进一步基于感兴趣区水平的功能连接方法 分析正负网络内和网络间功能连接的变化;最后,将卒中患者异常的功能连接指标与上肢运动功能评分进行相关性分析.结果 卒中组与病灶侧M1功能连接显著大于对照组的脑区均在负网络内;而显著小于对照组的脑区均在正网络内;卒中组正负网络内和网络间的功能连接强度均显著降低;且病灶侧M1与负网络内同侧额中回的功能连接系数与上肢运动功能评分呈负相关(r=-0.735,P<0.01).结论 脑卒中后与手运动相关脑区的正负网络连接强度均下降.尤其是卒中组大于对照组的功能连接可能并非意味相关脑区的"功能代偿",而是反映了手运动相关脑区之间的负性功能连接降低,这将更有利于深入理解脑卒中神经作用机制并为康复干预提供参考价值.  相似文献   
4.
目的 运用静息态功能磁共振成像(resting-state function magnetic resonance imaging,rs-fMRI)探究太极拳零基础者在太极拳不同学习阶段的脑功能活动的局部一致性(regional homogeneity,ReHo)变化.材料与方法 采用被试内设计,对18名太极拳零基础被试在太极拳学习初期(2周)和学习14周进行同样内容的静息态功能磁共振成像检查.然后分别计算前后两个不同时间点被试的全脑ReHo值并进行相关统计学分析.结果 与太极拳学习2周比较,太极拳学习14周被试右侧梭状回的ReHo值显著增高,而右侧小脑和左侧顶上小叶的ReHo值显著降低(AlphaSim校正P<0.05);其中右侧小脑的ReHo的变化值与太极拳技能评分的变化值呈显著负相关(r=-0.507,P=0.032).多元回归分析发现,太极拳学习2周被试的右侧颞中回、右侧前扣带回的ReHo值与太极拳技能评分的变化量呈显著正相关(r=0.908、0.818,P<0.01),而左侧枕下回及右侧颞上回的ReHo值与太极拳技能评分的变化量呈显著负相关(r=-0.474,P<0.05;r=-0.824,P<0.01).结论 研究结果 表明,随着太极拳学习技能水平的提高,被试的静息态功能活动局部一致性变化,反映了相关脑区可塑性.另外,太极拳学习初期某些脑区的ReHo值对太极拳技能学习效果有一定的潜在预测作用.  相似文献   
5.
目的运用磁共振扩散张量成像(diffusion tensor imaging,DTI)探究脑卒中皮质脊髓束(corticospinal tract,CST)扩散定量指标与运动功能的关系.材料与方法采集37例单侧皮质下脑卒中患者和30例健康被试的DTI数据,运用概率性纤维束成像追踪出健康被试的CST,获得健康对照组CST模板.基于健康对照组的CST模板测量两组被试双侧CST的各向异性分数(fractional anisotropy,FA)和平均扩散率(mean diffusivity,MD),进一步计算两组被试FA比率(FA ratio,rFA)、FA不对称性(FA asymmetry,FAasy)、MD比率(MD ratio,rMD)和MD不对称性(MD asymmetry,MDasy),用这六个扩散参数相关指标来评估脑卒中患者CST完整性损伤,并与患者"手+腕"及上肢运动功能评分(Fugl-Meyer Assessment,FMA)作相关性分析.结果与健康对照组相比,卒中组病灶同侧CST的FA、rFA显著降低(分别为t=-15.775,t=-11.111,P<0.001),FAasy显著增高(t=9.473,P<0.001);而MD、rMD显著增高(分别为t=9.553,t=7.733,P<0.001),MDasy显著降低(t=-8.941,P<0.001);病灶对侧CST的FA和MD均无显著变化(P>0.05).患者病程及病灶大小与各扩散指标间均无显著相关关系(P>0.05).卒中组病灶同侧CST的FA和rFA与"手+腕"及上肢FMA呈显著正相关(分别为r=0.342,P=0.038;r=0.479,P=0.003;r=0.343,P=0.038;r=0.482,P=0.003),FAasy与"手+腕"及上肢FMA呈显著负相关(分别为r=-0.353,P=0.032;r=-0.490,P=0.002).分步回归分析进一步发现,相较于病灶同侧CST的FA和rFA,FAasy与"手+腕"和上肢运动功能评分更加相关(分别为Beta=-0.353,P=0.032;Beta=-0.490,P=0.002).结论基于健康对照组CST模板测得的FA相关指标能反映CST结构完整性.FAasy与"手+腕"及上肢运动功能评分密切相关,或许可作为评估脑卒中患者手腕部和上肢运动功能障碍的重要参考指标.  相似文献   
6.
Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter. Correla-tion analysis was also performed to assess the association between age and both corneal and oeular higher-order aberrations. Results The mean Zemike coefficient of Z40 was (0.27±0.07) ?m (range,0.130~0.451). Al-though corneal Z40 increased slightly with age,the correlation was small and insignificant (r =0.172,p =0.069 ). However, ocular Z40 had a positive correlation with age (r =0.545,p =0.000 ). Analyzer showed positive correlations with age for both corneal (r=0.499,p =0.000) and ocular (r=0.427,p =0.000) HOAs. Positive correlations were also observed between age and both corneal (r=0.149,p =0.021 ) and ocular (r=0.253,p =0.007) TC. Corneal and ocular TT (r =0.344,p =0.000; r=0.185,p =0.050,respectively) were increased with age. No significant correlation was found between corneal TS and age (r =0.180,p =0.057 ), but TS of the whole eye in-creased with age (r =0.560,p =0.000). There was a positive correlation between corneal and ocular HOAs (r =0.327,p=0.000),TC (r=0.233 ,p=0.013),and TT (r=0.481 ,p=0.000) aberration. Conclusions These re-suits also suggest that the ocular HOAs,TC,and TT increase with age,mainly because of the increase in corneal HOAs,TC,and TT; and the ZAO aberration increases with age,mainly because of the increase in Z40 in the internal optics. Individual variability in corneal primary spherical aberration was observed in Chinese.Therefore, preoperative measurement of corneal Z40 is crucial to the selection of aspheric IOL.  相似文献   
7.
Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter. Correla-tion analysis was also performed to assess the association between age and both corneal and oeular higher-order aberrations. Results The mean Zemike coefficient of Z40 was (0.27±0.07) ?m (range,0.130~0.451). Al-though corneal Z40 increased slightly with age,the correlation was small and insignificant (r =0.172,p =0.069 ). However, ocular Z40 had a positive correlation with age (r =0.545,p =0.000 ). Analyzer showed positive correlations with age for both corneal (r=0.499,p =0.000) and ocular (r=0.427,p =0.000) HOAs. Positive correlations were also observed between age and both corneal (r=0.149,p =0.021 ) and ocular (r=0.253,p =0.007) TC. Corneal and ocular TT (r =0.344,p =0.000; r=0.185,p =0.050,respectively) were increased with age. No significant correlation was found between corneal TS and age (r =0.180,p =0.057 ), but TS of the whole eye in-creased with age (r =0.560,p =0.000). There was a positive correlation between corneal and ocular HOAs (r =0.327,p=0.000),TC (r=0.233 ,p=0.013),and TT (r=0.481 ,p=0.000) aberration. Conclusions These re-suits also suggest that the ocular HOAs,TC,and TT increase with age,mainly because of the increase in corneal HOAs,TC,and TT; and the ZAO aberration increases with age,mainly because of the increase in Z40 in the internal optics. Individual variability in corneal primary spherical aberration was observed in Chinese.Therefore, preoperative measurement of corneal Z40 is crucial to the selection of aspheric IOL.  相似文献   
8.
Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter. Correla-tion analysis was also performed to assess the association between age and both corneal and oeular higher-order aberrations. Results The mean Zemike coefficient of Z40 was (0.27±0.07) ?m (range,0.130~0.451). Al-though corneal Z40 increased slightly with age,the correlation was small and insignificant (r =0.172,p =0.069 ). However, ocular Z40 had a positive correlation with age (r =0.545,p =0.000 ). Analyzer showed positive correlations with age for both corneal (r=0.499,p =0.000) and ocular (r=0.427,p =0.000) HOAs. Positive correlations were also observed between age and both corneal (r=0.149,p =0.021 ) and ocular (r=0.253,p =0.007) TC. Corneal and ocular TT (r =0.344,p =0.000; r=0.185,p =0.050,respectively) were increased with age. No significant correlation was found between corneal TS and age (r =0.180,p =0.057 ), but TS of the whole eye in-creased with age (r =0.560,p =0.000). There was a positive correlation between corneal and ocular HOAs (r =0.327,p=0.000),TC (r=0.233 ,p=0.013),and TT (r=0.481 ,p=0.000) aberration. Conclusions These re-suits also suggest that the ocular HOAs,TC,and TT increase with age,mainly because of the increase in corneal HOAs,TC,and TT; and the ZAO aberration increases with age,mainly because of the increase in Z40 in the internal optics. Individual variability in corneal primary spherical aberration was observed in Chinese.Therefore, preoperative measurement of corneal Z40 is crucial to the selection of aspheric IOL.  相似文献   
9.
Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter. Correla-tion analysis was also performed to assess the association between age and both corneal and oeular higher-order aberrations. Results The mean Zemike coefficient of Z40 was (0.27±0.07) ?m (range,0.130~0.451). Al-though corneal Z40 increased slightly with age,the correlation was small and insignificant (r =0.172,p =0.069 ). However, ocular Z40 had a positive correlation with age (r =0.545,p =0.000 ). Analyzer showed positive correlations with age for both corneal (r=0.499,p =0.000) and ocular (r=0.427,p =0.000) HOAs. Positive correlations were also observed between age and both corneal (r=0.149,p =0.021 ) and ocular (r=0.253,p =0.007) TC. Corneal and ocular TT (r =0.344,p =0.000; r=0.185,p =0.050,respectively) were increased with age. No significant correlation was found between corneal TS and age (r =0.180,p =0.057 ), but TS of the whole eye in-creased with age (r =0.560,p =0.000). There was a positive correlation between corneal and ocular HOAs (r =0.327,p=0.000),TC (r=0.233 ,p=0.013),and TT (r=0.481 ,p=0.000) aberration. Conclusions These re-suits also suggest that the ocular HOAs,TC,and TT increase with age,mainly because of the increase in corneal HOAs,TC,and TT; and the ZAO aberration increases with age,mainly because of the increase in Z40 in the internal optics. Individual variability in corneal primary spherical aberration was observed in Chinese.Therefore, preoperative measurement of corneal Z40 is crucial to the selection of aspheric IOL.  相似文献   
10.
Objective To investigate age-related changes in corneal and ocular monochromatic high-er-order aberrations and elucidate the distribution of corneal primary spherical in Chinese. Methods Using Traeey-iTrace visual function analyzer (EyeSys corneal topography combined with a ray-tracing aberrometer),113 normal eyes of 59 Chinese,mean age of 33.81+20.50 years (range,5-73 years),were evaluated for corneal and ocular monochromatic total higher-order aberrations (HOAs), primary spherical aberration (Z40),total spherical (TS),total coma (TC),and total trefoil aberration (TT) in the central 6mm diameter. Correla-tion analysis was also performed to assess the association between age and both corneal and oeular higher-order aberrations. Results The mean Zemike coefficient of Z40 was (0.27±0.07) ?m (range,0.130~0.451). Al-though corneal Z40 increased slightly with age,the correlation was small and insignificant (r =0.172,p =0.069 ). However, ocular Z40 had a positive correlation with age (r =0.545,p =0.000 ). Analyzer showed positive correlations with age for both corneal (r=0.499,p =0.000) and ocular (r=0.427,p =0.000) HOAs. Positive correlations were also observed between age and both corneal (r=0.149,p =0.021 ) and ocular (r=0.253,p =0.007) TC. Corneal and ocular TT (r =0.344,p =0.000; r=0.185,p =0.050,respectively) were increased with age. No significant correlation was found between corneal TS and age (r =0.180,p =0.057 ), but TS of the whole eye in-creased with age (r =0.560,p =0.000). There was a positive correlation between corneal and ocular HOAs (r =0.327,p=0.000),TC (r=0.233 ,p=0.013),and TT (r=0.481 ,p=0.000) aberration. Conclusions These re-suits also suggest that the ocular HOAs,TC,and TT increase with age,mainly because of the increase in corneal HOAs,TC,and TT; and the ZAO aberration increases with age,mainly because of the increase in Z40 in the internal optics. Individual variability in corneal primary spherical aberration was observed in Chinese.Therefore, preoperative measurement of corneal Z40 is crucial to the selection of aspheric IOL.  相似文献   
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