Altered spontaneous brain activity patterns in patients with retinal vein occlusion indicated by the amplitude of low‑frequency fluctuation: A functional magnetic resonance imaging study

: The aim of the present study was to explore the amplitude of low-frequency fluctuations (ALFF; a measurement of spontaneous brain activity) in different brain regions of patients with retinal vein occlusion (RVO) and its association with vision changes measurements. A total of 24 RVO patients (12 males and 12 females) and 24 healthy controls (HCs, 12 males and 12 females) were recruited, and they were closely matched regarding age, gender and education level (classified according to nine-year compulsory education in China and higher education, all including primary school, junior school, high school and university). ALFF values of different brain regions were gathered and analyzed, and statistical analysis software was used to explore the correlations between the average ALFF signals and clinical features. The ability of ALFF values to distinguish between subjects with RVO and HCs was analyzed by receiver operating characteristic (ROC) curves. The results indicated that the subjects from the RVO group had higher ALFF values than the HCs in the posterior lobe of the left cerebellum, inferior temporal gyrus, cerebellar anterior lobe, right cerebellum posterior/anterior lobe, and lower ALFF values in the medial frontal gyrus, right precuneus, left middle frontal gyrus, right angular gyrus and right superior frontal gyrus. The ROC curve analysis of each brain region indicated that the accuracy of the area under the ROC curves regarding the prediction of RVO was excellent. The best-corrected visual acuity (VA) in the left eye was positively correlated with the ALFF value of the right precuneus (r=0.767, P=0.004) and the best-corrected VA in the right eye was positively correlated with the ALFF value of the left middle frontal gyrus (r=0.935, P<0.001). The central subfield retinal thickness in the left eye was negatively correlated with the ALFF value of the right precuneus (r=-0.895; P<0.001). The duration of RVO in the right eye was positively correlated with the ALFF value of the left middle frontal gyrus (r=0.868; P<0.001). In conclusion, the present results indicate that RVO is associated with dysfunction of diverse brain regions, including language- and movement-associated areas, which may reflect the underlying pathogenic mechanisms of RVO (trial registry no. CDYFY-LL-2017025).