AbstractPurposeTo compare the diagnostic performance of the capillary density (CD) of the central 1–6 mm and peripheral 6–12 mm annular regions in detecting open‐angle glaucoma in high myopia (HM) using 15 × 12 mm wide‐field swept‐source optical coherence tomography angiography (WF SS‐OCTA).MethodsThe study enrolled 206 and 103 eyes with HM and highly myopic open‐angle glaucoma (HM‐OAG), respectively. WF SS‐OCTA images centred on the fovea were obtained to analyse the changes in the CD in the 1–3 mm, 3–6 mm, 6–9 mm, and 9–12 mm annular regions. CD of the superficial capillary plexus (SCP) was measured with the built‐in software. The area under the receiver operating characteristic curve (AUROC) of each region was compared.ResultsThe diagnostic performance of the SCP CD in the central 1–6 mm annular region (AUROC = 0.849) was better than that in the peripheral 6–12 mm annular region (AUROC = 0.756, p = 0.001). The annular AUROCs of SCP CD peaked in the 3–6 mm annular region (AUROC = 0.858) and gradually decreased with increasing diameter and were lower than the corresponding AUROCs of the ganglion cell–inner plexiform layer thickness (p < 0.05 for all comparisons). SCP CD of the inferior quadrant in the 3–6 mm annular region had the best diagnostic performance (AUROC = 0.859).ConclusionThe SCP CD in the central 1–6 mm annular region exhibited better diagnostic performance for the detection of HM‐OAG in HM. The assessment of more peripheral regions has no added value in detecting glaucoma in HM.