School of Optometry, Faculty of Health and Social Science, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Research Centre for SHARP Vision, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Sci Rep. 2022 May 2;12(1):7104. doi: 10.1038/s41598-022-11087-x.
Due to excessive elongation of the eyeball, myopia-related vascular abnormalities are frequently observed in the central retinal artery (CRA) and its intraretinal branches. In addition to inconsistency in previously reported findings, hemodynamic (reduced flow velocity, increased vascular resistance) and morphological changes (narrower vessel diameter) were usually studied separately. This cross-sectional study evaluated the hemodynamic and morphological characteristics concurrently in a large sample of healthy myopes, by using the color Doppler ultrasound and adaptive optics retinal camera. Results showed that the retrobulbar segment of CRA had a tendency of slightly reduced flow velocity in eyeballs with longer axial length, but the correlation was not significant after adjusting for the multiple correlations. Vascular resistance was not affected by the axial elongation. With respect to the intraretinal branches, no significant changes in longer eyes of total diameter or lumen diameter were observed, while both the wall thickness and the wall cross-sectional area were significantly increased, but only a marginally increase in the wall to lumen ratio was found with increasing axial length. This implies some potential small artery remodeling in the intraretinal CRA branches. Overall, blood supply of the inner retina in healthy young myopes is likely to be maintained. Additionally, morphological parameters of vascular microstructure could be potential biomarkers to monitor myopia progression and understand myopia-related vascular abnormalities in future studies.
由于眼球过度伸长，近视相关的血管异常经常在视网膜中央动脉（CRA）及其视网膜内分支中观察到。除了先前报道的结果不一致外，血流动力学（血流速度降低，血管阻力增加）和形态学变化（血管直径变窄）通常是分开研究的。这项横断面研究通过彩色多谱勒超声和自适应光学视网膜照相机，在大量健康近视者中同时评估了血流动力学和形态特征。结果表明，在眼轴较长的眼球中，CRA 的球后段血流速度有略微降低的趋势，但在调整多重相关性后，相关性并不显著。血管阻力不受轴向伸长的影响。对于视网膜内分支，在更长的总直径或管腔直径的眼睛中没有观察到明显的变化，而壁厚度和壁横截面积显著增加，但是随着轴向长度的增加，仅发现壁腔比略有增加。这意味着视网膜内 CRA 分支中可能存在一些潜在的小动脉重塑。总的来说，健康年轻近视者的内视网膜血液供应可能得到维持。此外，血管微观结构的形态参数可能是未来研究中监测近视进展和了解近视相关血管异常的潜在生物标志物。
