[Clinical observation of spontaneous brain activity in children with congenital cortical cataract amblyopia]

Objective: To investigate the characteristics of spontaneous brain activity in children with congenital cortical cataract amblyopia. Methods: A cross-sectional study was conducted. Twenty cases of unilateral congenital cortical cataract amblyopia (unilateral amblyopia group) and 14 cases of bilateral congenital cortical cataract amblyopia (bilateral amblyopia group) were enrolled from January 2022 to December 2022 at the First Affiliated Hospital of Zhengzhou University. Seventeen age and gender matched children with normal visual acuity were recruited as the healthy control group. Resting-state functional MRI (fMRI) was performed on all participants, and the amplitude of low-frequency fluctuations (ALFF) technique was used to analyze their spontaneous brain activities. The original ALFF value of each voxel was divided by the average ALFF value of the whole brain to obtain the standardized ALFF value (referred to as ALFF value), which reflected the intensity of spontaneous brain activity in different brain regions. General demographic data were compared using one-way analysis of variance, Kruskal-Wallis test, and chi-square test. Comparison of ALFF values was conducted using one-way analysis of variance. Results: There were no significant differences in age, gender, distribution of amblyopic eye or non-dominant eye, and degree of refractive error among the three groups (all P>0.05). Compared to the healthy control group, the unilateral amblyopia group showed higher ALFF values in the right posterior lobe of the cerebellum (67 voxels, t=3.48) and left posterior lobe of the cerebellum (71 voxels, t=4.09), and lower ALFF values in the right postcentral gyrus (91 voxels, t=-3.91), right inferior parietal lobule (73 voxels, t=-4.88), right inferior frontal gyrus (78 voxels, t=-4.09), left inferior parietal lobule (556 voxels, t=-4.82), and left inferior frontal gyrus (122 voxels, t=-4.27) (all P<0.01). The bilateral amblyopia group showed higher ALFF values in the right insula (60 voxels, t=3.54), right Rolandic operculum (69 voxels, t=3.73), right posterior lobe of the cerebellum (54 voxels, t=3.43), and left posterior lobe of the cerebellum (143 voxels, t=3.69), and lower ALFF values in the left inferior frontal gyrus (99 voxels, t=-4.39), left postcentral gyrus (231 voxels, t=-4.28), and right inferior parietal lobule (54 voxels, t=-3.77) (all P<0.01). Compared to the unilateral amblyopia group, the bilateral amblyopia group showed higher ALFF values in the left middle frontal gyrus (52 voxels, t=3.15, P=0.029), left posterior lobe of the cerebellum (77 voxels, t=3.39, P=0.001), and right Rolandic operculum (53 voxels, t=3.59, P=0.007). Conclusion: Children with congenital cortical cataract amblyopia exhibit altered spontaneous brain activity in multiple brain regions, and there are differences in spontaneous brain activity changes between unilateral and bilateral amblyopia.