Wave-based optical coherence elastography (OCE) is a rapidly emerging technique for elasticity assessment of tissues having high displacement sensitivity and simple implementation. However, most current noncontact wave excitation techniques are unable to target a specific tissue site in 3D and rely on transversal scanning of the imaging beam. Here, we demonstrate that dye-loaded perfluorocarbon nanoparticles ("nanobombs") excited by a pulsed laser can produce localized axially propagating longitudinal shear waves while adhering to the laser safety limit. A phase correction method was developed and implemented to perform sensitive nanobomb elastography using ~1.5 MHz Fourier domain mode locking laser. The nanobomb activation was also monitored by detecting photoacoustic signals. The highly localized elastic waves detected by the nanobomb OCE (nb-OCE) suggest possibility of high-resolution 3D elastographic imaging. OCIS codes: (110.4500) Optical coherence tomography; (170.0110) imaging system; (150.1135) Algorithms Changes in tissue viscoelasticity are often associated with development of different pathologies, and can, therefore, be a useful biomarker for monitoring disease onset and progression [1]. Wave-based optical coherence elastography (OCE) is an emerging powerful technique capable of nanometer-scale displacement sensitivity, which has enabled biomechanical assessments of tissues with minimal excitation forces [2], such as pneumatic, Lorentz, and acoustic radiation forces. However, these techniques usually cannot target *
Cataract is one of the most prevalent causes of blindness around the world. Understanding the mechanisms of cataract development and progression is important for clinical diagnosis and treatment. Cold cataract has proven to be a robust model for cataract formation that can be easily controlled in the laboratory. There is evidence that the biomechanical properties of the lens can be significantly changed by cataract. Therefore, early detection of cataract, as well as evaluation of therapies, could be guided by characterization of lenticular biomechanical properties. In this work, we utilized optical coherence elastography (OCE) to monitor the changes in biomechanical properties of ex vivo porcine lenses during formation of cold cataract. Elastic waves were induced in the porcine lenses by a focused micro air-pulse while the lenses were cooled, and the elastic wave velocity was translated to Young's modulus of the lens. The results show an increase in the stiffness of the lens due to formation of the cold cataract (from 11.3 AE 3.4 to 21.8 AE 7.8 kPa). These results show a relation between lens opacity and stiffness and demonstrate that OCE can assess lenticular biomechanical properties and may be useful for detecting and potentially characterizing cataracts.
We present an erratum to correct an inadvertent error made during the
calculations of the in-focus fluence of pulsed laser used to excite
nanoparticles [Opt.
Lett. 44, 3162
(2019)OPLEDP0146-959210.1364/OL.44.003162] and to update the
conclusion regarding laser safety limits achieved with this type of
excitation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.