Objective To detecte the pathogenetic mechanism of cortical deficit in persons with strabismic amblyopia by blood oxygenation level dependent-functional magnetic resonance imaging(BOLD-fMRI)． Methods The data of BOLD-fMRI of occipital visual cortex in 11 persons with strabismic amblyopia and 8 healthy ones were collected by 1．5T MRI system．The results of binocular pixel exponent in strabismic amblyopia group was compared with that in the normal group and the result of and average activation of cortical neuron in strabismic amblyopia group was analyzed.Results The binocular pixel exponent was lower in the strabismic amblyopia group(14．13％±4．55％)than that in the normal group(47．82％±5．34％)(PConclusions The reduction of cortical binocular cells and the undersampling and coding of higher-spatial-frequency components of visual stimuli may be related to the strabismic amblyopia．BOLD-fMRI may provide a new path to detecte the pathoffenetic mechanism of cortical deficit in people with strabismic amblyopia. (Chin J Ocul Fundus Dis，2004，20：19-22)
Amblyopia is a visual development deficit caused by abnormal visual experience in early life, mainly manifesting as defected visual acuity and binocular visual impairment, which is considered to reflect abnormal development of the brain rather than organic lesions of the eye. Previous studies have reported abnormal spontaneous brain activity in patients with amblyopia. However, the location of abnormal spontaneous activity in patients with amblyopia and the association between abnormal brain function activity and clinical deficits remain unclear. The purpose of this study is to analyze spontaneous brain functional activity abnormalities in patients with amblyopia and their associations with clinical defects using resting-state functional magnetic resonance imaging (fMRI) data. In this study, 31 patients with amblyopia and 31 healthy controls were enrolled for resting-state fMRI scanning. The results showed that spontaneous activity in the right angular gyrus, left posterior cerebellum, and left cingulate gyrus were significantly lower in patients with amblyopia than in controls, and spontaneous activity in the right middle temporal gyrus was significantly higher in patients with amblyopia. In addition, the spontaneous activity of the left cerebellum in patients with amblyopia was negatively associated with the best-corrected visual acuity of the amblyopic eye, and the spontaneous activity of the right middle temporal gyrus was positively associated with the stereoacuity. This study found that adult patients with amblyopia showed abnormal spontaneous activity in the angular gyrus, cerebellum, middle temporal gyrus, and cingulate gyrus. Furthermore, the functional abnormalities in the cerebellum and middle temporal gyrus may be associated with visual acuity defects and stereopsis deficiency in patients with amblyopia. These findings help explain the neural mechanism of amblyopia, thus promoting the improvement of the treatment strategy for amblyopia.
ObjectiveTo evaluate the changes in subfoveal choroidal thickness (SFCT) in amblyopic eyes.MethodsA evidence-based medicine study. Chinese and English as search terms for amblyopia and choroid was used to search literature in Wanfang, CNKI, and PubMed of National Library of Medicine. Incomplete or irrelevant literature and review literature were excluded. The literature was meta-analyzed using STATA 15.0. The weighted mean difference (WMD) and 95% confidence interval (CI) were selected as the estimated value of effect size, and subgroup analysis and sensitivity analysis were used to detect the source of heterogeneity.ResultsAccording to the search strategy, 75 articles were initially retrieved, and 15 articles were finally included for meta-analysis. A total of 650 patients with amblyopia, aged 3 to 65 years old, were included. The enhanced depth imaging technology of spectral domain optical coherence tomography was used to measure SFCT. The results of meta analysis showed that SFCT of amblyopic eyes was more effective than the contralateral eye (WMD=18.89 μm, 95% CI 14.81-22.98 μm, P＜0.001) and normal eyes were thicken (WMD=39.49 μm, 95% CI 33.88-45.09 μm, P＜0.001). There was no statistically significant difference in SFCT between anisometropic and strabismic amblyopia eyes (WMD=－5.03 μm, 95% CI －19.50-9.44 μm, P=0.495).ConclusionsThe SFCT of amblyopic eyes in amblyopic patients is thicker than that of the contralateral eye and normal eyes. There is no difference in SFCT between anisometropia and strabismus amblyopia.
目的:分析探讨单眼散光弱视患儿对比敏感度(CS)视功能的受损特点。方法:对正常儿童组36例、单眼散光弱视组34例、单眼非散光弱视组33例,共103例,用静态F.A.C.T图表和计算机Gabor斑CS检查程序分别检查患儿对侧眼、弱视眼及90°和180°两主子午线方向上的对比敏感度。结果:①单眼散光弱视组和单眼非散光弱视组的对侧眼、弱视眼的CS值在所有空间频率均较正常组的CS降低(Plt;0.05),表现为中、高空间频率区CS的明显受损(Plt;0.01)。②单眼散光弱视组的弱视眼在90°和180°两主子午线方向上的对比敏感度有显著差异(Plt;0.01)。结论:弱视儿童的对侧眼不正常。用计算机Gabor斑检查可以了解弱视散光儿童不同子午线上的CS存在的差异,明确定位弱子午线,并可以针对子午线性弱视,进一步开展知觉学习的治疗。
Objective To investigate the characteristic of the multifocal visual evoked potentials(MVEP)and the visual function across the visual field in anisometropic amblyopes and isometropic amblyopes. Methods MVEP from 32 anisometropic amblyopic eyes and 31 control eyes were tested. Results In anisometropic amblyopic eyes,the latencies of MVEP were significantly prolonged．The amplitudes of MVEP were significantly attenuated in the central region of the visual field,and these phenomena gradually reduced with the increase of the eccentricity． Conclusion The visual function of anisometropic amblyopic eyes is reduced more significantly in the central region than in the peripheral region of the visual field. (Chin J Ocul Fundus Dis,20000,16:27-29)