Microstructure of Parapapillary Atrophy Is Associated With Parapapillary Microvasculature in Myopic Eyes

Abstract

To evaluate the clinical characteristics of beta-parapapillary atrophy (β-PPA) in myopic eyes and determine whether the microstructure of β-PPA is associated with parapapillary microvasculature by using optical coherence tomography (OCT) angiography. Cross-sectional study. This study included 80 subjects with myopia with β-PPA. Spherical equivalent (SE) refractive error, axial length, horizontal tilt angle, and the width of β-PPA were evaluated. The microstructure of β-PPA and subfoveal choroidal thickness were evaluated using enhanced-depth imaging OCT and eyes were classified into 3 groups based on the presence of Bruch membrane (BM): a PPA+BM-only group, a PPA+BM and PPA-BM group, and a PPA-BM-only group. Superficial and deep parapapillary vessel density was measured using OCT angiography. Clinical characteristics were compared among the groups and linear regression analysis was performed to explore the relationship between the parapapillary microvasculature and microstructure of β-PPA. The mean axial length and SE refractive error of the participants were 26.47 ± 1.17mm and -6.28 ± 2.71 diopters, respectively. The PPA+BM-only group had a more inferiorly rotated optic disc (P= .025), larger β-PPA (P < .001), and lower superficial and deep parapapillary vessel density (both P < .001) compared with those of the PPA-BM-only group. Multivariate linear regression analysis showed that the average PPA+BM width on horizontal scans was significantly associated with superficial and deep parapapillary vessel density (P= .034 and P= .003, respectively). Significant differences were observed in the microvasculature according to the microstructure of β-PPA. PPA+BM width was closely correlated with superficial and deep parapapillary vessel density. Longitudinal studies are needed to elucidate the role of β-PPA in the development and progression of glaucoma in myopic eyes.