Contribution of the retinal contour to the peripheral optics of human eye

Understanding the relationship between the retinal contour and peripheral aberrations is fundamental for exploring the mechanism of myopia progression. Not much has been known about how the retinal expansion can affect peripheral aberrations across the two-dimensional visual field. This study aims to quantify and analyze the changes in the lower- and higher-order aberrations across the visual field induced by retinal expansion, and to understand how this relationship can be influenced by axial astigmatism and the misalignments in the ocular components. Retinal expansion was represented by translating retinal points along the chief rays in the vitreous humor. A realistic eye model was constructed incorporating astigmatism, misalignments and other irregular features based on measurement data. Three-dimensional ray tracing was performed on this model and its two symmetric versions to analyze the changes of axial and peripheral aberrations induced by retinal expansion. The results show that spherical equivalent refraction changes the most during retinal expansion with the rate of -4 to -3 D/mm, which is around 10 times larger than the plus cylinder power. Axial astigmatism determines the retinal impacts on peripheral astigmatism, and unique patterns were found near the two peripheral field locations with zero cylinder power. Ocular misalignments mainly affect higher-order aberrations, especially third-order coma. For most optical features, the impacts of retinal expansion are stronger for larger eccentricity. The impacts of retinal expansion on the lower- and higher-order aberrations have been systematically characterized for the two-dimensional visual field, showing unique patterns in the presence of astigmatism and ocular misalignments.