Choroidal thickness, but not retinal thickness, correlated closely with axial length and refractive diopters in Chinese children. Choroid thinning occurs before retina thinning early in myopic progression.

Purpose This study aimed to explore the characteristics of retinal perfusion and its associations with high myopia. Methods A total of 760 participants were included. Peripapillary radial peripapillary capillary perfusion, foveal avascular zone, and parafoveal perfusion were measured using optical coherence tomography angiography (OCTA). Tilted disc ratio and parapapillary atrophy were determined using swept-source optical coherence tomography. Results A total of 760 young healthy participants with myopic eyes were included in the analysis. The mean axial length and titled disc ratio were 26.43 ± 1.14 and 0.76 ± 0.08 mm in the high-myopia group and 24.79 ± 0.75 and 0.80 ± 0.09 mm in the control group, respectively. The high-myopia group exhibited significantly larger parapapillary atrophy, lower tilted disc ratio, lower radial peripapillary capillary vessel density, larger area of foveal avascular zone, and lower deep parafoveal vessel density. In the multivariate analysis, titled disc ratio significantly correlated with radial peripapillary capillary vessel density (P = 0.0134), larger foveal avascular zone (P = 0.0062), and lower deep parafoveal vessel density (P < 0.0001). Conclusions Reduced radial peripapillary capillary and deep parafoveal vessel density and enlarged area of foveal avascular zone were observed in high myopia. Tilted disc ratio correlated with retinal perfusion.

In Chinese children, the ChT is thinnest in the nasal quadrant and thicker in central regions than in peripheral areas. The subfoveal ChT independently decreases with age, axial length, preterm history, and increases with height.