Purpose <p>To measure structural and microvascular alterations of the optic nerve head in high myopia and correlate the measured parameters with the visual field mean sensitivity defect.</p> Methods <p>Thirty-two control eyes and 53 eyes with high myopia were analysed to quantify the thickness of the peripapillary retinal nerve fibre layer (pRNFL) and density of radial peripapillary capillary (RPC) perfusion. The pRNFL thickness, RPC perfusion density and other parameters were compared between the two groups and correlations between structural/microvascular alterations and visual field mean deviation (MD) were determined. Receiver operating characteristic curves were used to determine the diagnostic accuracy of RPC perfusion density and pRNFL thickness in high myopia.</p> Results <p>Global RPC perfusion density and pRNFL thickness were significantly lower in the high myopic group than in the control group (all <i>p</i> &lt; 0.01). The area under the curve (AUC) of global RPC perfusion density for discriminating high myopia from controls was 0.83, which was higher than that for global pRNFL thickness (0.63). The AUC of RPC perfusion density for discriminating visual field defects (MD &lt; −2 dB) was 0.74 (<i>p</i> &lt; 0.001), while global pRNFL thickness did not show a significant AUC (<i>p</i> = 0.20). For high myopia, the correlation coefficient between global RPC perfusion density and MD was numerically higher (<i>r</i> = 0.41, <i>p</i> = 0.003) than that between global pRNFL thickness and MD (<i>r</i> = 0.29, <i>p</i> = 0.04). In contrast, no statistically significant correlations were observed between RPC perfusion density, pRNFL thickness and MD in the control group (all <i>p</i> &gt; 0.05).</p> Conclusions <p>Peripapillary structural and microvascular alterations occur in high myopia with a marked decrease in RPC perfusion density, which may be a more sensitive indicator of visual field defects.</p>