Clinical features of superficial and deep peripapillary microvascular density in healthy myopic eyes

PURPOSE To evaluate the clinical features of peripapillary microvasculature in myopic eyes and investigate the association between the superficial and deep peripapillary microvascular density and the myopic optic disc characteristics. MATERIALS AND METHODS This cross-sectional study included one hundred and fifty healthy myopic eyes with β-peripapillary atrophy (β-PPA). Ovality index, degree of optic disc rotation, and the area of β-PPA were measured. Superficial and deep peripapillary microvascular density was measured using optical coherence tomography angiography. Logistic regression analysis was performed to look for the factors associated with peripapillary microvascular reduction. RESULTS The mean superficial peripapillary microvascular density was 62.14 ± 5.47%; 33 (22.0%) participants were found to have decreased microvascular density. Increased axial length (p < 0.001) and decreased average peripapillary retinal nerve fiber layer thickness (p = 0.027) were associated with the superficial peripapillary microvascular reduction. The mean deep peripapillary microvascular density was 73.76 ± 4.02%; 26 (17.33%) participants were found to have decreased microvascular density. Larger ovality index (p = 0.028) and more inferiorly rotated optic disc (p = 0.021) were associated with the deep peripapillary microvascular reduction. CONCLUSIONS Axial elongation was significantly associated with microvascular reduction in the superficial peripapillary retina, whereas it was not associated with deep peripapillary microvascular reduction. The deep peripapillary microvascular density was independently associated with myopic optic disc characteristics such as ovality index and optic disc rotation.