Objective To investigate the effect of myopia on retinal vascular geometry in young subjects. Methods A retrospective cross-sectional study. From June 2018 to December 2018, 235 participants (235 eyes) who took part in routine physical examination in Huadong Sanatorium were included . There were 94 males and 141 females; age was (34.89±6.15) years old; equivalent spherical refraction (SE) was (－3.78±3.25) D. 59 (25.11%, 59/235) were divided into high myopia group (SE≤－6.0 D), along with 131 (55.74%, 131/235) low to moderate myopia group (－0.5 D＞SE＞－6.0 D), and 45 (19.15%, 45/235) emmetropia group (0.5 D≥SE≥－0.5 D). Retinal vascular geometric measurements, including central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), fractal dimension arteriole (FDa), fractal dimension venule (FDv), curvature tortuosity arteriole (CTORTa), curvature tortuosity venule, branch angle arteriole (BAa), branch angle venule, branch coefficient arteriole and branching coefficient venule, were extracted by using a validated computer program. One-way analysis of variance and analysis of covariance were performed to compare the measurements across the high myopia, low to moderate myopia, and emmetropia groups. Linear regression analysis was used to explore the relationship between SE and retinal vascular geometric parameters. ResultsThe differences in CRAE (F=65.11), CRVE (F=61.52), FDa (F=14.26), FDv (F=8.31), CTORTa (F=5.07) and BAa (F=6.51) among eys of high myopia group, low to moderate myopia group and emmetropia group remained significant (P＜0.05) after adjusting for age, glycosylated hemoglobin, mean arterial pressure, body mass index, and intraocular pressure. CRAE and CRVE were linearly correlated with the SE (P＜0.05). FDa, FDv, cTORTa and BAa decreased with the decrease of SE in high myopia (P＜0.05). ConclusionsMyopia is associated with the change of the retinal vascular geometric characteristics. With the deepening of myopia, the change of retinal vascular geometric characteristics gradually worsens.