Distribution of the retinal microcirculation based on the morphology of peripapillary atrophy in high myopia

Introduction: To evaluate the retinal microvasculature of the optic nerve head and macula in high myopia (HM), investigate the association between the vascular parameters and peripapillary atrophy deformation, and assess and identify the peripapillary atrophy morphology changes during the development of HM. Methods: 167 right eyes from 167 HM patients were enrolled in this cross-sectional study. Using the optical coherence tomography angiography (OCTA) and fundus camera, we evaluated the following parameters: radian and type of peripapillary atrophy (PPA), intrapapillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), and foveal avascular zone (FAZ). Based on the PPA radian, subjects were divided into four groups: the non-PPA, temporal PPA, advanced PPA, and annular PPA. At the same time, the above parameters were compared between the groups using analysis of variance (ANOVA) and least significant difference(LSD) test. Results: Total enrolled patients were divided into the non-PPA group (22 eyes), temporal-PPA group (70 eyes), advanced-PPA group (60 eyes), and annular-PPA group (15 eyes). The results showed that the PVD in the annular-PPA group was smaller than that in the non-PPA group, especially in the superonasal (SN), nasosuperior (NS), nasoinferior (NI), inferotemporal (IT), temporoinferior (TI), and superotemporal (ST) directions (F=4.059, 5.014, 2.830, 4.798, 5.892, 3.439; P<0.05). Notably, the PVD showcased the highest value in temporal, followed by that in superior and inferior, and the lowest in nasal. Concerning the fovea deep macular vascular density (fovea-DMVD), FAZ area, and subfoveal choroidal thickness (SFCT) in the annular-PPA group, they were less than those of the rest of the groups (P< 0.05). Conclusion: The retinal microvasculature differed significantly in HM according to the PPA morphology. In addition to PVD and SFCT, the PPA can also affect FAZ. Finally, we speculated that PVD demonstrated better predictability of myopic progression than MVD.