Li Qian, Zhai Liying, Jiang Qinying, Qin Wen, Li Qingji, Yin Xiaohui, Guo Mingxia
Department of Radiology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.
School of Medical Imaging, Tianjin Medical University, Tianjin, China.
Neurosci Lett. 2015 Jun 15;597:7-12. doi: 10.1016/j.neulet.2015.04.027. Epub 2015 Apr 18.
Amblyopia is a neurological disorder of vision that follows abnormal binocular interaction or visual deprivation during early life. Previous studies have reported multiple functional or structural cortical alterations. Although white matter was also studied, it still cannot be clarified clearly which fasciculus was affected by amblyopia. In the present study, tract-based spatial statistics analysis was applied to diffusion tensor imaging (DTI) to investigate potential diffusion changes of neural tracts in anisometropic amblyopia. Fractional anisotropy (FA) value was calculated and compared between 20 amblyopic children and 18 healthy age-matched controls. In contrast to the controls, significant decreases in FA values were found in right optic radiation (OR), left inferior longitudinal fasciculus/inferior fronto-occipital fasciculus (ILF/IFO) and right superior longitudinal fasciculus (SLF) in the amblyopia. Furthermore, FA values of these identified tracts showed positive correlation with visual acuity. It can be inferred that abnormal visual input not only hinders OR from well developed, but also impairs fasciculi associated with dorsal and ventral visual pathways, which may be responsible for the amblyopic deficiency in object discrimination and stereopsis. Increased FA was detected in right posterior part of corpus callosum (CC) with a medium effect size, which may be due to compensation effect. DTI with subsequent measurement of FA is a useful tool for investigating neuronal tract involvement in amblyopia.
弱视是一种视觉神经紊乱疾病，源于生命早期双眼相互作用异常或视觉剥夺。先前的研究报告了多种功能性或结构性皮质改变。尽管对白质也进行了研究，但仍无法明确弱视影响了哪一束神经纤维。在本研究中，基于束的空间统计学分析应用于扩散张量成像（DTI），以研究屈光参差性弱视中神经束的潜在扩散变化。计算了20名弱视儿童和18名年龄匹配的健康对照者的分数各向异性（FA）值并进行比较。与对照组相比，弱视组右侧视辐射（OR）、左侧下纵束/额枕下束（ILF/IFO）和右侧上纵束（SLF）的FA值显著降低。此外，这些已确定神经束的FA值与视力呈正相关。可以推断，异常的视觉输入不仅阻碍视辐射的正常发育，还损害与背侧和腹侧视觉通路相关的神经束，这可能是弱视患者在物体辨别和立体视觉方面存在缺陷的原因。在胼胝体（CC）右侧后部检测到FA增加，效应量中等，这可能是由于补偿作用。随后测量FA的DTI是研究弱视中神经元束受累情况的有用工具。
