To investigate the microstructural features of parapapillary gamma zone and beta zone and their relationship with three-dimensional optic disc shape in non-myopic eyes. Methods: This cross-sectional study included 62 non-myopic eyes with parapapillary gamma or beta zone and 70 control eyes. On the spectral domain optical coherent tomography (SD-OCT) images, we measured the area of gamma zone and beta zone, the length of border tissue, and related disc parameters. The disc ovality index, disc

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... ation degrees around three axes, Bruch's membrane opening (BMO) ovality ratio were calculated based on the SD-OCT images. Results: The parapapillary gamma zone composed by externally oblique border tissue was found in inferior, nasal and temporal quadrants of the non-myopic eyes. The presence of gamma zone in non-myopic eyes was correlated with smaller disc ovality index, larger rotation degree around vertical and horizontal axes, and larger BMO ovality ratio (P<0.001). Compared with the non-temporal gamma zone group, eyes with temporal gamma zone had a longer axial length and rotated more around vertical axes (P<0.001). Multivariate analysis showed that the area of gamma zone was correlated with the disc ovality index (P<0.001). The presence and area of beta zone was correlated with age (P<0.01). Conclusions: In non-myopic eyes, the parapapillary gamma zone composed by external oblique border tissue was significantly associated with the disc ovality and disc rotations around vertical and horizontal axes. From a biomechanical perspective, parapapillary gamma zone may contribute to the optic disc stability in association with the structure of BMO.