Ophthalmology (HZ, WG, HL), The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; Radiology (QW, HH, XX, FW), The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; State Key Laboratory of Reproductive Medicine (JD, ZH), Nanjing Medical University, Nanjing, China; and Epidemiology (JD, ZH), School of Public Health, Nanjing Medical University, Nanjing, China.
J Neuroophthalmol. 2023 Dec 1;43(4):557-562. doi: 10.1097/WNO.0000000000001865. Epub 2023 May 11.
To investigate structural and functional changes of brain in children with intermittent exotropia (IXT) and their relationship with clinical features.
Twenty-one IXT patients (mean age 9.38 ± 2.62 years) and 21 age-, gender-, education-, and handedness-matched healthy controls (HCs, mean age 9.52 ± 3.28 years) underwent high-resolution T1 imaging, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI). The gray and white matter volume analyzed by voxel-based morphometry (VBM) based on T1 imaging, the fractional anisotropy (FA) and mean diffusivity (MD) indices based on DTI, and the amplitude of low frequency fluctuation (ALFF) value based on rs-fMRI were compared between these 2 groups. The correlations between MRI-derived parameters in significant brain regions and various clinical characteristics of IXT were analyzed.
Compared with HCs, IXT children showed significantly decreased FA in right precentral gyrus (PRG) and right postcentral gyrus (POG), and significantly decreased ALFF in bilateral calcarine sulcus, bilateral cuneus, left lingual gyrus, and left superior occipital gyrus. The FA value in right PRG and right POG was negatively correlated with disease duration (r = -0.520, P = 0.016), angle of exodeviation at near (r = -0.549, P = 0.010), and angle of exodeviation at distance (r = -0.547, P = 0.010).
IXT children exhibited abnormalities of white matter microstructure and reduced spontaneous neural activities in brain regions involving in oculomotor performance and binocular fusion. Further studies are needed to determine whether these findings are related to the neuropathologic mechanism or downstream changes of IXT.
探讨间歇性外斜视（IXT）患儿脑结构和功能的变化及其与临床特征的关系。
21 例间歇性外斜视患儿（平均年龄 9.38±2.62 岁）和 21 例年龄、性别、教育程度和利手相匹配的健康对照组（HCs，平均年龄 9.52±3.28 岁）接受高分辨率 T1 成像、弥散张量成像（DTI）和静息态功能磁共振成像（rs-fMRI）检查。基于 T1 成像的体素形态学（VBM）分析灰质和白质体积，基于 DTI 的各向异性分数（FA）和平均弥散度（MD）指数，以及基于 rs-fMRI 的低频波动振幅（ALFF）值，比较两组间的差异。分析各显著脑区 MRI 相关参数与 IXT 患儿各种临床特征的相关性。
与 HCs 相比，IXT 患儿右侧中央前回（PRG）和右侧中央后回（POG）FA 值显著降低，双侧距状沟、双侧楔叶、左侧舌回和左侧顶叶上回 ALFF 值显著降低。右侧 PRG 和右侧 POG 的 FA 值与疾病持续时间（r=-0.520，P=0.016）、近距斜视度（r=-0.549，P=0.010）和远距斜视度（r=-0.547，P=0.010）呈负相关。
IXT 患儿脑白质微观结构异常，涉及眼球运动和双眼融合的脑区自发神经活动减少。需要进一步研究这些发现是否与 IXT 的神经病理学机制或下游变化有关。
