Distribution of the Retinal Microcirculation Based on the Morphology of Peripapillary Atrophy in High Myopia

Abstract

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. Keywords: high myopia; peripapillary atrophy; optic nerve head; morphology; vascular density

Multimodal imaging of optic nerve head abnormalities in high myopia

“…The outer boundary of PPA was delineated as the visible scleral edge in color photographs, aligning with the termination of the hyperreflective region in infrared (IR) images. Based on size and morphological features, a succinct classification scheme, including temporal PPA (confined to the temporal aspect of the optic disk), advanced PPA (extending to both superior and inferior aspects of the optic disk), and annular PPA (encompassing the entire peripapillary region), is introduced to intuitively indicate the severity of myopia ( 15 ). Lu et al developed a computer-aided measuring tool, enabling the quantification of PPA size on two-dimensional fundus images, marking the first instance of such quantification ( 16 ).…”

“…OCTA enables the exploration of choroidal microcirculation features within PPA. Tang et al observed a reduction in peripapillary vessel density (PVD) in patients’ eyes, notably in the superior nasal (SN), nasal superior (NS), nasal inferior (NI), inferior temporal (IT), temporal inferior (TI), and superior temporal (ST) directions, accompanied by a significant expansion of PPA area ( 15 ). The OCTA choroid map delineated a localized microvasculature dropout (MvD) within the beta zone-PPA region, consistent with hypofluorescence observed in indocyanine green angiography (ICGA) ( 22 ).…”