Age-related viscoelasticity changes in rabbit lens measured by optical coherence elastography

Abstract

The biomechanical properties of the crystalline lens play a critical role in eye health and vision. In this study, we used focused acoustic radiation force (ARF) to induce surface waves in young and mature rabbit lenses in situ and to measure the viscoelastic properties of the lenses inside the eyeball. Phase-sensitive optical coherence elastography (OCE) system was used to image the wave propagation, and the wave dispersion was quantified by spectral analysis. The results show that the dispersion of the ARF-induced elastic waves was different between the young (N=5) and mature (N=10) lenses. Young’s modulus and shear viscosity coefficient were quantified based on a Scholte wave model. The results show that both elasticity and viscosity are significantly different between the young and mature lenses. The Young’s modulus of the lenses increased with age from 7.74±1.56 kPa (young) to 15.15±4.52 kPa (mature), and the shear viscosity coefficient increased from 0.55±0.04 Pa·s (young) to 0.86±0.13 Pa·s (mature). In conclusion, the combination of ARF excitation, OCE imaging, and dispersion analysis enabled non-invasive quantification of lenticular viscoelasticity in situ.