【作者】 杨磊；

【导师】 燕振国；

【作者基本信息】 兰州大学 ， 眼科学， 2012， 硕士

【摘要】 目的：本研究采用血氧水平依赖性功能性磁共振成像(Blood oxygen level dependent-function magnetic resonance imaging, BOLD-fMRI)技术,研究屈光参差性弱视儿童在规范弱视训练前后,立体视觉映射的脑皮层的功能变化,确定儿童屈光参差性弱视临床治疗的真正终点。方法：初诊屈光参差性弱视患儿11例(男6例,女5例),年龄5.5～11岁,平均(8.6±3.35)岁。将被试分为5.5～7岁组和8-11岁组；所有被试均为远视性弱视,中心凹注视；屈光参差范围3.0D～6.0D；均为右利手；所有被试无眼部及神经系统疾患；MRI检查时排除由视网膜至外侧膝状体核间的疾病。试验前充分矫正屈光不正；规范化弱视训练后1周、2周及4周时复查fMRI。实验数据由SIEMENS MAGNETOM Verio3T磁共振扫描系统获取。视觉刺激呈现采用脑功能视听觉刺激系统(SAMRTEC,SA-9900)。任务设计程序均采用E-Prime2.0软件编写。刺激模式采用对比度接近80%的随机点立体图像,患儿采用佩戴红蓝眼镜获得双眼立体视觉。采用组块式(blocks)设计,由激活状态(activation state)和控制状态(control state)组成,分别是交替的随机点立体图像与固定于屏幕中央的黑色“+”图标。试验数据导入一台64位操作系统工作站,进行离线处理。采用基于MATLAB7.12.0.635(The MathWorks, Inc.)的SPM8(Statistical Parametric Mapping)软件包进行数据分析。高斯平滑的半高宽度(Full-width at half maximum, FWHM)为6mm。采用随机效应法分别获得各组脑皮层激活的矩阵数据,对被试治疗前及治疗后1周、2周及4周时相应脑皮层激活范围的差异进行自身前后配对t检验(阈值设定为P<0.001时具有统计学意义,未多重矫正)。结果：1.当设定P值为0.05,激活范围阈值为6个体素时,两年龄组间大脑皮层激活无显著差异；2.自身前后对照分析结果显示,各治疗阶段较前具有显著地激活差异,主要集中在双侧枕叶(BA18)、舌回(BA17)、枕中回(BA19)及双侧顶上小叶(BA7),以右枕叶(BA18)最显著；1周时双侧枕中回(BA19)小面积激活；2周时左侧顶上小叶(BA7)与双侧顶叶(BA40)小面积激活；4周后左侧顶上小叶(BA7)激活；3.治疗2~4周时,脑皮层视功能区的增进幅度滞后于随机点立体视。结论：1.儿童屈光参差性弱视对与立体觉相关脑皮层的功能损害严重,短期内恢复困难。2.屈光参差性弱视治疗的效果在一定程度上取决于患儿对疾病的认识与配合程度。3.脑皮层视功能区的功能重建速度滞后于临床上广泛应用的随机点立体视锐度的恢复速度。因此,随机点立体视觉检查无法全面评价弱视治疗效果。4.伴随立体视觉的建立,视皮层的中枢激活由双侧枕叶向顶叶等多个脑功能区延伸。更多还原

【Abstract】 Objective: The aim of this study was to evaluate the recovery about the visual cortex function of stereopsis in anisometropic amblyopia before and after regular amblyopia treatment with blood oxygenation level dependent functional MRI techniques (BOLD-fMRI), and to confirm the real destination that children with anisometropic amblyopia in the clinical treatment.Methods: In this study, fMRI experiment was performed on eleven children with first amblyopic treatment, six males and five females, age from5.5to11, average age was8.6±3.35, divided into5.5-7and8-11years of age groups, the binocular diopter difference was3.0D-6.0D. They were all hyperopic amblyopia, central vision type and right handedness. They didn’t have eye and neurological disease except for amblyopia. All were not have any disease that was from retina to corpus geniculatum laterale after MRI inspection. Must be correct ametropia, and review fMRI inspection after regular amblyopia treatment one week, two weeks and one month.Data were acquired by SIEMENS MAGNETOM Verio3.0Tesla MR imaging system, carried out by the visual stimulus system (SAMRTEC, SA-9900) produced by Shenzhen Sinorad Medical Electronics Inc. Visual stimulus was designed using E-Prime2.0. During the study, the contrast ratio of random-dot stereograms (R.D.S) was approximate80%, the patients were asked to view stimuli through red-blue filtered stereo glasses. Blocks design mode was used by the activation state and control state composition, the activation task was a series of R.D.S pictures, and the control task was a solid black cross centered on the gray background.All data imported a workstations which operating system was64bit, and they were processed by using SPM8(Statistical Parametric Mapping) which based on the MATLAB7.12.0.635(The Math Works, Inc.). Full-width at half maximum (FWHMR) was6mm. Random effect group analysis was performed in each group to acquire average cerebral cortex activated functional images data. The different mapping between each group during stereograms stimulus was also acquired. The differences range of activated area were compared by matched t-test (P＜0.001, not multiple correction), before and after regular amblyopia treatment one week, two weeks and one month.Results:(1) The cerebral cortex activated area still no significant difference between the two age groups, when set to P value was0.05and activated threshold for six voxels.(2) Before-after study show that every treatment phase is obvious differences than before, it mainly in bilateral occipital lobe (BA18), lingualis gyrus of the occipital lobe (BA17), middle occipital gyrus (BA19), and the bilateral parietal lobe (BA7), the right BA18was most significant; After one weeks:the bilateral BA19activated on the small area; After two weeks:the left BA7and bilateral BA40were activated on small area; After four weeks:the left BA7expanded in different levels.(3) From two to four weeks, the functional reconstruction’s speed of the cerebral cortex lag behind the recovery speed of the R.D.S inspection.Conclusion:(1) In children anisometropic amblyopia, the visual cortical functional mediating stereopsis was damaged seriously and not easy to treat in a short time;(2) The effect of amblyopia’s treatment depends on the extent which is understanding of disease and the cooperating with treatment;(3) The functional reconstruction’s speed of the visual cortex lag behind the recovery speed of the random-dot stereograms inspection in clinical application widely. Therefore, R.D.S inspection can’t integrality evaluate the effect of amblyopia cure;(4) With the establishment of the stereopsis, the range of visual cortical functional activated expansion from bilateral occipital lobe to parietal lobe and other brain regions.更多还原