| 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. |
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