Assessing corneal cross-linking with reverberant 3D optical coherence elastography

Abstract

. Significance: Corneal cross-linking (CXL) is a well-known procedure for treating certain eye disorders such as keratoconus. However, characterization of the biomechanical changes in the cornea as a result of this procedure is still under active research. Specifically, there is a clinical need for high-resolution characterization of individual corneal layers. Aim: A high-resolution elastography method in conjunction with a custom optical coherence tomography system is used to track these biomechanical changes in individual corneal layers. Pre- and post-treatment analysis for both low-dose and high-dose CXL experiments are performed. Approach: A recently developed elastography technique that utilizes the theory of reverberant shear wave fields, with optical coherence tomography as the modality, is applied to pig corneas ex vivo to evaluate elasticity changes associated with corneal CXL. Sets of low-dose and high-dose CXL treatments are evaluated before and after treatments with three pairs of pig corneas per experiment. Results: The reverberant three-dimensional (3D) optical coherence elastography (OCE) technique can identify increases in elasticity associated with both low-dose and high-dose CXL treatments. There is a notable graphical difference between low-dose and high-dose treatments. In addition, the technique is able to identify which layers of the cornea are potentially affected by the CXL procedure and provides insight into the nonlinearity of the elasticity changes. Conclusions: The reverberant 3D OCE technique can identify depth-resolved changes in elasticity of the cornea associated with CXL procedures. This method could be translated to assess and monitor CXL efficacy in various clinical settings.

Fluid compartments influence elastography of the aging mouse brain

“…Select frames in time are averaged to obtain the final 3D elastogram. Details on this methodology are adapted from previous studies (Zvietcovich et al 2019 , Ge et al 2022b ). All elastogram estimations and data processing are completed in MATLAB 2022b (Mathworks, Natick, MA, USA).…”

Reverberant magnetic resonance elastographic imaging using a single mechanical driver

“…Under these conditions, the two-dimensional autocorrelation function of the complex wave field and the phase gradient provides fast and accurate estimates of the wavenumber from which shear wave speed and modulus are derived. Reverberant elastography has been demonstrated with ultrasound (Parker et al 2017 ) and optical coherence tomography (Zvietcovich et al 2019 , Ge et al 2022 ) using multiple point drivers. However, to our knowledge, this is the first reported study demonstrating its utility with MRE and its feasibility in the brain using a single mechanical driver.…”

Multifocal acoustic radiation force-based reverberant optical coherence elastography for evaluation of ocular globe biomechanical properties

“…This technique stands out for its superior elasticity resolution when compared to the USE previously reported 11 and superior mechanical contrast compared to traditional wave-based OCE. 18 Furthermore, unlike conventional RevOCE methods that utilize mechanical shakers that physically contact tissues directly, which can potentially compromise the integrity of delicate tissues while inducing a reverberant field, 18 , 42 , 43 the presented technique relies on ARF, which does not necessitate direct contact between the actuator and the sample, making it more convenient for in vivo applications. By providing a more complete understanding of the interrelationship of the biomechanical properties of the different ocular components, this technique can have important implications for both research and clinical practice.…”