Peripheral Contrast Reduction Optically Induced by Scattering Lenses Thickens Peripheral Choroid

Abstract

Purpose The mechanisms underlying a myopia control strategy using scattering lenses are unclear. Therefore, this study investigates the short-term effects of scatter lenses on central and peripheral choroidal thickness and axial length, which serve as a biomarker in myopia progression research. Methods In total, 23 participants underwent a 60-minute lens wear phase each to five lens conditions: medium peripheral scattering, high peripheral scattering, medium full-field scattering, high full-field scattering and control (clear lens). Central and peripheral choroidal thickness, foveal axial length, and central visual acuity were measured before and after each lens wear condition. Results Peripheral choroidal thickening was found after the lens wear phase of the medium peripheral scattering condition (+3.91 ± 5.37 µm, P = 0 . 04), revealing a significant difference to the control lens condition ( P = 0.004), most pronounced in the superior peripheral retina (+1.95 ± 10.74 µm, P = 0.02). In the central retina, significant choroidal thickening was only found in the nasal part after exposure to medium full-field scattering (+3.91 ± 11.72 µm) compared to the control condition ( P = 0.001). High peripheral and full-field scattering conditions did not significantly affect central or peripheral choroidal thickness. Visual acuity was significantly reduced in the full-field scattering conditions compared to control and peripheral scattering lenses, with no improvement after 60-minute lens wear. Axial length did not differ significantly after 60-minute exposure to any scattering lens condition or when compared to the control lens. Conclusions The results indicate a local retinal contrast detection mechanism signals the choroid to thicken peripherally after adaptation to medium peripheral scattering but not high peripheral scattering or full-field scattering at all, while central thickening was only significant nasally after exposure to medium full-field scattering. This emphasizes the importance of the peripheral retina and the level of contrast reduction in the context of myopia research. Translational Relevance This finding gives insight into the mechanism behind the myopia control strategy inducing peripheral scattering.