ScholarWorks@동국대학교

초록

Purpose:To evaluate the locations of beta-zone and gamma-zone parapapillary atrophy (PPA) in nonmyopic eyes.Methods:A total of 151 nonmyopic eyes with an axial length (AXL) of <24.0 mm were included in this cross-sectional study. From the Bruch membrane opening (BMO), the angular locations of the maximal width of beta-zone PPA (without retinal pigment epithelium) and gamma-zone PPA (without Bruch membrane) were compared with that of the central retinal vascular trunk (CRVT)/BMO offset, as a surrogate of lamina cribrosa/BMO offset. Based on the extent and direction of the CRVT/BMO offset, patients were classified into 3 groups: (1) minimal offset (offset index <0.2), (2) temporal offset, and (3) nasal offset.Results:Sixty-four eyes had minimal offset, 53 eyes had a temporal offset, and 34 had a nasal offset. The CRVT/BMO offset showed significant angular correlations with beta-zone PPA (r=-0.209, P=0.026) and gamma-zone PPA (r=-0.529, P<0.001). Presence of beta-zone PPA was associated with older age [odds ratio (OR)=1.119, P<0.001], longer AXL (OR=2.260, P=0.011), and the presence of gamma-zone PPA (OR=8.952, P<0.001). Among 56 eyes with gamma-zone PPA, 26 eyes (46.4%) had their gamma-zone PPAs on the nasal side, which was associated with the superotemporal direction of the CRVT/BMO offset (OR=1.008, P=0.003).Conclusions:Both beta-zone and gamma-zone PPAs were found in nonmyopic eyes. Nasally located gamma-zone PPA was associated with the temporal direction of CRVT/BMO offset, like a mirrored image of myopic PPA. gamma-zone PPA is not restricted to myopia but represents the offset between the openings of the optic nerve head canal.

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