AIM:To investigate peripapillary vessel density and its relationship with other ocular parameters in highly myopic eyes with peripapillary intrachoroidal cavitation(PICC), and to analyze risk factors for PICC.

METHODS:Cross-sectional study. A total of 35 highly myopic eyes with PICC, 40 highly myopic eyes without PICC and 35 normal eyes were included in this study. All participants underwent fundus photography and spectral-domain optical coherence tomography(SD-OCT). OCT angiography was also performed to image the retinal vasculature in the peripapillary areas of different sectors, including the radial peripapillary capillaries(RPC)and optic nerve head(ONH)layer. The difference of morphology changes in optic disc and peripapillary vessel density between these three groups were compared. Correlations between peripapillary vessel density and PICC and risk factors for the presence of PICC were analyzed.

RESULTS: Significant differences were found among the three groups in spherical equivalent refraction(SER), best-corrected visual acuity(BCVA), axial length, peripapillary atrophy β-zone(β-PPA)area, retinal nerve fiber layer(RNFL)thickness and the presence of tilted optic disc, posterior staphyloma and myopic maculopathy(MMD)(P<0.05). There were significant differences among the three groups in the peripapillary vessel density both in RPC(54.34±5.58, 57.54±7.44, 64.42±3.50)and ONH(51.24±7.43, 52.75±9.96, 61.25±4.15)layers(P<0.001). In highly myopic eyes, vessel density was significantly lower in eyes with PICC than in those without in inferotemporal area both in the RPC(56.76±6.62,63.84±6.02,67.52±4.78)and ONH(56.47±5.79,60.38±4.72,64.18±4.37)layers. The vessel density was significantly correlated with the presence of MMD, β-PPA area and RNFL thickness in the RPC layer, whereas correlated with the presence of MMD, PICC and RNFL thickness in the ONH layer(P<0.05). Tilted optic disc and posterior staphyloma were independent risk factors for the presence of PICC(OR=8.007, 95%CI: 2.045-31.348; OR=7.558, 95%CI: 1.398-50.026).

CONCLUSION:Highly myopic eyes with PICC had relatively lower peripapillary vessel densities, especially in the temporal area, than those without. Tilted optic disc and posterior staphyloma were independent risk factors for the presence of PICC.