目的：通过光学相干断层扫描血管成像技术(OCTA)观察与比较不同屈光度近视青少年儿童黄斑区血管密度和视网膜厚度的变化，并探讨其相关性。方法：前瞻性横断面研究。纳入6～18岁青少年儿童115例230眼。根据等效球镜度数(SE)分为4组：正视组16例32眼，低度近视组47例94眼，中度近视组34例68眼，高度近视组18例36眼。RTVueXR扫描黄斑区6mm×6mm范围，系统自动分区，分为以黄斑中心小凹为中心，直径分别为1mm的中心凹(fovea)环、1～3mm的内环(parafovea)、3～6mm的外环(perifovea)，且每个圆环被进一步划分为颞(T)、上(S)、鼻(N)、下(I)4个象限，定量分析各分区浅层、深层毛细血管密度和视网膜厚度。结果：正视、低度、中度和高度近视组黄斑区整体浅层毛细血管密度依次显著减低，分别为(44.4±3.5)%、(44.8±3.8)%、(44.3±3.8)%、(42.6±4.5)%(F=2.963，P=0.033)，内环颞侧浅层毛细血管密度分别为(46.1±3.5)%、(46.8±5.1)%、(46.2±4.3)%、(43.8±5.5)%(F=3.436，P=0.018)； 四组黄斑区整体深层毛细血管密度随着近视度数增加亦显著降低，分别为(49.9±4.1)%、(48.4±4.7)%、(47.9±5.5)%、(45.3±4.7)%(F=4.806，P=0.003)，外环深层毛细血管密度分别为(49±4.4)%、(47.2±5.2)%、(46.6±6)%、(43.6±5.1)%(F=5.495，P=0.001)。四组黄斑区整体视网膜厚度分别为293.9±12.9、295.5±13.0、290.9±12.0、284.5±10.7μm(F=6.606，P<0.001)。内环颞侧、鼻侧浅层毛细血管密度与SE呈正相关(r=0.221、0.219，P=0.001、0.001)，外环颞侧、上方、鼻侧、下方深层毛细血管密度与SE呈正相关(r=0.172、0.200、0.250、0.296，P=0.011、0.003、<0.001、<0.001)； 黄斑区除中心凹外其余区域视网膜厚度与SE均呈正相关(P<0.05)。结论：随着青少年儿童近视度数的增加，黄斑区浅层毛细血管密度降低，以内环颞侧为甚； 深层毛细血管密度降低，以外环范围内为甚； 视网膜厚度降低，以内环和外环范围为甚。青少年儿童近视随着屈光度增加，会导致黄斑区结构和血流循环的变化，在高度近视眼中改变尤为显著。

AIM: To observe and compare the changes of macular vascular density and retinal thickness in children and adolescents with different degrees using optical coherence tomography angiography(OCTA), then analyze their correlation.METHODS: Our prospective cross-sectional study included 230 eyes of 115 children and adolescents aged 6-18a. According to spherical equivalent power(SE), they were divided into four groups: emmetropia group(32 eyes of 16 cases), mild myopia group(94 eyes of 47 cases), moderate myopia group(68 eyes of 34 cases), and high myopia group(36 eyes of 18 cases). Using RTVue XR scans of the 6mm×6mm region of the macula, the system automatically divided it into three rings: 1mm(fovea)ring, 1mm-3mm(parafovea)ring, and 3mm-6mm(perifovea)ring. And each ring was further divided into four quadrants: temporal(T), superior(S), nasal(N), and inferior(I). Quantitatively analysis was performed for the superficial and deep capillary densities and retinal thickness of each sector.RESULTS: The superficial capillary density in the macula was in turn significantly decreased as in emmetropia(44.4±3.5)%, mild myopia(44.8±3.8)%, moderate myopia(44.3±3.8)%, and high myopia(42.6±4.5)% groups(F=2.963,P=0.033). The superficial capillary density of parafovea's temporal side were(46.1±3.5)%,(46.8±5.1)%,(46.2±4.3)%, and(43.8±5.5)% in the four groups, respectively(F=3.436, P=0.018). Similarly, the deep capillary density of the four groups was(49.9±4.1)%,(48.4±4.7)%,(47.9±5.5)%, and(45.3±4.7)%, respectively(F=4.806, P=0.003). The deep capillary density of the perifovea was(49±4.4)%,(47.2±5.2)%,(46.6±6)%, and(43.6±5.1)% in the 4 groups, respectively(F=5.495, P=0.001). The retinal thickness of the four groups was 293.9±12.9, 295.5±13.0, 290.9±12.0, and 284.5±10.7 μm(F=6.606, P<0.001). The superficial capillary densities of parafoveal's temporal and nasal sides were positively correlated with SE(r=0.221, 0.219, P=0.001, 0.001). The deep capillary density of perifovea's temporal, superior, nasal and inferior side were positively correlated with SE(r=0.172, 0.200, 0.250, 0.296, P=0.011, 0.003, <0.001, <0.001). The central retinal thickness except the fovea were positively correlated with SE(P<0.05).CONCLUSION: With the increase of myopia degree of children and adolescents, the superficial capillaries density in the macula decreases, especially in the parafovea's temporal side; as well as the deep capillaries density, especially decreases in the perifovea. The central retinal thickness decreases in both parafovea and perifovea. With the myopia degree of children and adolescents increases, the structure and capillary circulation of the macula will be influenced, especially in the high myopia group.

四川省科技厅资助项目(No.2020JDKP0072); 四川省卫健委资助项目(No.20PJ135); 西南医科大学科研项目(No.2019ZQN040); 泸州市校联合科研项目(No.2017LZXNYD-J01)