Supplementary Material for: Changes in dimensions and functions of crystalline lens in high myopia using CASIA2 optical coherence tomography

Introduction: Crystalline lens is the major dioptric component and varies with refractive status. In this study, we aim to evaluate the changes of dimensions and functions of crystalline lens in high myopia and its correlated variables using CASIA2 swept-source optical coherence tomography (SS-OCT). Methods: One hundred and thirty eligible eyes of myopic patients from 18-40 years old were enrolled and divided into low-to-moderate myopia (LMM) and high myopia (HM) groups according to spherical equivalent (SE). Anterior segment features, including lens thickness (LT), anterior radius of curvature (ARC), posterior radius of curvature (PRC), anterior chamber depth (ACD) and lens tilt were obtained by CASIA2. Lens power was calculated using Bennett’s formula. Sixty-seven participants were imaged at static state and accommodative state induced by −3 diopter (D) stimulus. Results: Compared to LMM group, HM group exhibited a significantly reduction in LT, ARC and lens tilt (all P<0.01). Each parameter correlated positively with SE (all P<0.01). Lens power increased with LT and tilt (r=0.42, 0.45), but decreased with ARC and axial length (AL) (r=-0.37, -0.62) among highly myopic eyes. Multivariate regression analysis revealed that lower lens power appeared to be independently associated with axial elongation in both groups (LMM: β=–1.124, P=0.002; HM: β=–1.603, P<0.001, respectively). Decreases in ARC and ACD were accompanied by accommodative response in each group, while PRC reduced during accommodation (P=0.009) only in high myopia. Conclusions: Young adults with high myopia presented the thinner thickness, smaller tilt, less lens power and higher accommodative response. Lens shape was closely associated with SE, however AL was a meaningful indicator of lens power.