Changes in Dimensions and Functions of Crystalline Lens in High Myopia Using CASIA2 Optical Coherence Tomography

Abstract

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.

Autostereoscopic 3D viewing can change the dimensions of the crystalline lens in myopes

“…These results agree with previous studies and provide more evidence of the classic theories of accommodation. 12,[24][25][26] The anterior radii of curvature have been reported to decrease by 0.6-0.8 mm per dioptre change in accommodative stimulus when measured with the OCT. 12,25,27,28 The corresponding changes in the present study were in the same direction but of a smaller magnitude, which may have been caused by differences in the refractive status of the enrolled participants, 29 accommodative stimuli 30 and measuring methods. The results of the present study suggest that 2D viewing would not induce dynamic changes in the eyes.…”

Building Tilt Scanning Measurement Based on Binary Linear Regression Analysis

“…The traditional feature extraction of heavy points adopts a manual visual method. This algorithm is simple and easy to implement, and there may be some unexpected errors in the extraction process due to subjective influence [8]. In tilt monitoring, fixed control targets or special extraction methods are usually used to get the characteristics of key points.…”

Age-Related Changes in Total Corneal Astigmatism in Eyes With High Myopia

“…E yes with high myopia exhibit many specific characteristics in ocular biometry. The anterior chamber is deeper, 1,2 the lens and choroidal thickness are thinner, [3][4][5] and posterior vitreous detachment progresses faster in eyes with high myopia than in eyes without high myopia. [6][7][8] Corneal biometry studies demonstrated that the corneal curvature is also flatter and the corneal thickness is thinner in highly myopic eyes.…”