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Frigelli M, Büchler P, Kling S. Dynamic evaluation of corneal cross-linking and osmotic diffusion effects using optical coherence elastography. Sci Rep 2024; 14:16614. [PMID: 39025900 PMCID: PMC11258322 DOI: 10.1038/s41598-024-67278-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 07/09/2024] [Indexed: 07/20/2024] Open
Abstract
Dynamic deformation events induced by osmosis or photochemical stiffening substantially influence geometrical and mechanical assessments in post-mortem corneas, therefore need to be carefully monitored in experimental settings. In this study, we employed optical coherence elastography (OCE) to quantify dynamic deformation processes at high resolution in freshly enucleated porcine corneas. Osmotic effects were studied by immerging n = 9 eyes in preservation media of three different tonicities. Dynamic processes underlying corneal cross-linking (CXL) were studied by subjecting n = 6 eyes to standard Dresden treatment, while three control groups were used. The entire procedures were performed under an OCE setup during up to 80 min, acquiring a volumetric scan every 20 s. Changes in OCE-derived axial deformations were incrementally calculated between consecutive scans. Preservation conditions had a strong influence on the observed strain patterns, which were consistent with the tonicity of the medium (swelling in hypotonic, deswelling in hypertonic environment). In the CXL group, we observed deswelling of the anterior stroma 10 min after starting the UV irradiation, which was not observed in any control group (p = 0.007). The presented results proved OCE to be a valuable technique to quantify subtle dynamic biomechanical alterations in the cornea resulting from CXL and preservation solutions.
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Affiliation(s)
- Matteo Frigelli
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Philippe Büchler
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland
| | - Sabine Kling
- ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
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2
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Zhang Z, Yang X, Zhao Z, Zeng F, Ye S, Baldock SJ, Lin H, Hardy JG, Zheng Y, Shen Y. Rapid imaging and product screening with low-cost line-field Fourier domain optical coherence tomography. Sci Rep 2023; 13:10809. [PMID: 37402736 DOI: 10.1038/s41598-023-37646-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/25/2023] [Indexed: 07/06/2023] Open
Abstract
Fourier domain optical coherence tomography (FD-OCT) is a well-established imaging technique that provides high-resolution internal structure images of an object at a fast speed. Modern FD-OCT systems typically operate at speeds of 40,000-100,000 A-scans/s, but are priced at least tens of thousands of pounds. In this study, we demonstrate a line-field FD-OCT (LF-FD-OCT) system that achieves an OCT imaging speed of 100,000 A-scan/s at a hardware cost of thousands of pounds. We demonstrate the potential of LF-FD-OCT for biomedical and industrial imaging applications such as corneas, 3D printed electronics, and printed circuit boards.
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Affiliation(s)
- Zijian Zhang
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, L7 8TX, UK
| | - Xingyu Yang
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Zhiyi Zhao
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Feng Zeng
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Sicong Ye
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Sara J Baldock
- Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK
| | - Hungyen Lin
- School of Engineering, Lancaster University, Lancaster, LA1 4YW, UK
- Materials Science Institute, Lancaster University, Lancaster, LA1 4YB, UK
| | - John G Hardy
- Department of Chemistry, Lancaster University, Lancaster, LA1 4YB, UK
- Materials Science Institute, Lancaster University, Lancaster, LA1 4YB, UK
| | - Yalin Zheng
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, L7 8TX, UK.
| | - Yaochun Shen
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
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Alexandrovskaya YM, Kasianenko EM, Sovetsky AA, Matveyev AL, Zaitsev VY. Spatio-Temporal Dynamics of Diffusion-Associated Deformations of Biological Tissues and Polyacrylamide Gels Observed with Optical Coherence Elastography. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2036. [PMID: 36903151 PMCID: PMC10004177 DOI: 10.3390/ma16052036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
In this work, we use the method of optical coherence elastography (OCE) to enable quantitative, spatially resolved visualization of diffusion-associated deformations in the areas of maximum concentration gradients during diffusion of hyperosmotic substances in cartilaginous tissue and polyacrylamide gels. At high concentration gradients, alternating sign, near-surface deformations in porous moisture-saturated materials are observed in the first minutes of diffusion. For cartilage, the kinetics of osmotic deformations visualized by OCE, as well as the optical transmittance variations caused by the diffusion, were comparatively analyzed for several substances that are often used as optical clearing agents, i.e., glycerol, polypropylene, PEG-400 and iohexol, for which the effective diffusion coefficients were found to be 7.4 ± 1.8, 5.0 ± 0.8, 4.4 ± 0.8 and 4.6 ± 0.9 × 10-6 cm2/s, respectively. For the osmotically induced shrinkage amplitude, the influence of the organic alcohol concentration appears to be more significant than the influence of its molecular weight. The rate and amplitude of osmotically induced shrinkage and dilatation in polyacrylamide gels is found to clearly depend on the degree of their crosslinking. The obtained results show that observation of osmotic strains with the developed OCE technique can be applied for structural characterization of a wide range of porous materials, including biopolymers. In addition, it may be promising for revealing alterations in the diffusivity/permeability of biological tissues that are potentially associated with various diseases.
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Affiliation(s)
- Yulia M. Alexandrovskaya
- Institute of Applied Physics of the Russian Academy of Sciences, Uljanova St., 46, 603950 Nizhny Novgorod, Russia
- Federal Scientific Research Center “Crystallography and Photonics”, Institute of Photon Technologies, Russian Academy of Sciences, 2 Pionerskaya Street, Troitsk, 108840 Moscow, Russia
| | - Ekaterina M. Kasianenko
- Institute of Applied Physics of the Russian Academy of Sciences, Uljanova St., 46, 603950 Nizhny Novgorod, Russia
- Federal Scientific Research Center “Crystallography and Photonics”, Institute of Photon Technologies, Russian Academy of Sciences, 2 Pionerskaya Street, Troitsk, 108840 Moscow, Russia
| | - Alexander A. Sovetsky
- Institute of Applied Physics of the Russian Academy of Sciences, Uljanova St., 46, 603950 Nizhny Novgorod, Russia
| | - Alexander L. Matveyev
- Institute of Applied Physics of the Russian Academy of Sciences, Uljanova St., 46, 603950 Nizhny Novgorod, Russia
| | - Vladimir Y. Zaitsev
- Institute of Applied Physics of the Russian Academy of Sciences, Uljanova St., 46, 603950 Nizhny Novgorod, Russia
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4
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Retinal and Corneal Changes Associated with Intraocular Silicone Oil Tamponade. J Clin Med 2022; 11:jcm11175234. [PMID: 36079165 PMCID: PMC9457190 DOI: 10.3390/jcm11175234] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/13/2022] [Accepted: 09/01/2022] [Indexed: 12/22/2022] Open
Abstract
Silicone oils (SO) are used as long-term intraocular tamponades and have an irreplaceable role in vitreoretinal surgery. They can, however, be associated with multiple and potentially severe complications, involving different ocular tissues, in particular retina and cornea. Recent advances in ophthalmic imaging have allowed the precise characterization of retinal and corneal microstructural changes, at a subclinical level. This detailed analysis of SO-related retinal and corneal changes has improved our understanding of their pathogenesis and offer the potential for optimized monitoring and management of patients with SO-filled eyes. This review aims to provide clinicians and ophthalmic scientists with an updated and comprehensive overview of the corneal and retinal changes associated with SO tamponade.
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Lawman S, Mason S, Kaye SB, Shen YC, Zheng Y. Accurate In Vivo Bowman's Thickness Measurement Using Mirau Ultrahigh Axial Resolution Line Field Optical Coherence Tomography. Transl Vis Sci Technol 2022; 11:6. [PMID: 35930278 PMCID: PMC9363679 DOI: 10.1167/tvst.11.8.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to assess the accuracy, repeatability, and performance limits of in vivo Mirau ultrahigh axial resolution (UHR) line field spectral domain (LF-SD) optical coherence tomography (OCT) for the measurement of Bowman's and epithelial thickness, and to provide a reference range of these values for healthy corneas. Methods Volunteers with no history and evidence of corneal disease were included in this study. An in vivo graph search image segmentation of the central cornea was obtained at the normal interface vector orientation. The Mirau-UHR-LF-SD-OCT system used has an axial resolution down to 2.4 µm in air (1.7 µm in tissue), with an A-scan speed of 204.8 kHz and a signal to noise ratio (sensitivity) of 69 (83) dB. Results Nine volunteers were included, one of whom wore contact lenses. The repeatability of mean Bowman's and epithelial thicknesses were 0.3 and 1.0 µm, respectively. The measured 95% population range for healthy in vivo thickness was 13.7 to 19.6 µm for the Bowman's layer, and 41.9 to 61.8 µm for the epithelial layer. Conclusions The measured thicknesses of Bowman's layer and the corneal epithelium using the Mirau-UHR-LF-SD-OCT were both accurate, with the range for healthy in vivo thicknesses matching prior confocal and OCT systems of varying axial resolutions, and repeatable, equaling the best value prior reported. Translational Relevance T1. Development of a commercially viable clinical UHR OCT technology, enabling accurate measurement and interpretation of Bowman's and epithelial layer thickness in clinical practice.
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Affiliation(s)
- Samuel Lawman
- University of Liverpool, Faculty of Science and Engineering, Department of Electrical Engineering and Electronics, Liverpool, UK.,University of Liverpool, Faculty of Health & Life Sciences, Department of Eye and Vision Science, Liverpool, UK
| | - Sharon Mason
- University of Liverpool, Faculty of Health & Life Sciences, Department of Eye and Vision Science, Liverpool, UK
| | - Stephen B Kaye
- University of Liverpool, Faculty of Health & Life Sciences, Department of Eye and Vision Science, Liverpool, UK
| | - Yao-Chun Shen
- University of Liverpool, Faculty of Science and Engineering, Department of Electrical Engineering and Electronics, Liverpool, UK
| | - Yalin Zheng
- University of Liverpool, Faculty of Health & Life Sciences, Department of Eye and Vision Science, Liverpool, UK
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6
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Alexandrovskaya Y, Baum O, Sovetsky A, Matveyev A, Matveev L, Sobol E, Zaitsev V. Optical Coherence Elastography as a Tool for Studying Deformations in Biomaterials: Spatially-Resolved Osmotic Strain Dynamics in Cartilaginous Samples. MATERIALS (BASEL, SWITZERLAND) 2022; 15:904. [PMID: 35160851 PMCID: PMC8838169 DOI: 10.3390/ma15030904] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/14/2022] [Accepted: 01/20/2022] [Indexed: 12/15/2022]
Abstract
This paper presents a recently developed variant of phase-resolved Optical Coherence Elastography (OCE) enabling non-contact visualization of transient local strains of various origins in biological tissues and other materials. In this work, we demonstrate the possibilities of this new technique for studying dynamics of osmotically-induced strains in cartilaginous tissue impregnated with optical clearing agents (OCA). For poroelastic water-containing biological tissues, application of non-isotonic OCAs, various contrast additives, as well as drug solutions administration, may excite transient spatially-inhomogeneous strain fields of high magnitude in the tissue bulk, initiating mechanical and structural alterations. The range of the strain reliably observed by OCE varied from ±10-3 to ±0.4 for diluted and pure glycerol, correspondingly. The OCE-technique used made it possible to reveal previously inaccessible details of the complex spatio-temporal evolution of alternating-sign osmotic strains at the initial stages of agent diffusion. Qualitatively different effects produced by particular hydrophilic OCAs, such as glycerol and iohexol, are discussed, as well as concentration-dependent differences. Overall, the work demonstrates the unique abilities of the new OCE-modality in providing a deeper insight in real-time kinetics of osmotically-induced strains relevant to a broad range of biomedical applications.
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Affiliation(s)
- Yulia Alexandrovskaya
- Institute of Photon Technologies, Federal Scientific Research Center “Crystallography and Photonics”, Russian Academy of Sciences, 2 Pionerskaya Street, Troitsk, 108840 Moscow, Russia;
| | - Olga Baum
- Institute of Photon Technologies, Federal Scientific Research Center “Crystallography and Photonics”, Russian Academy of Sciences, 2 Pionerskaya Street, Troitsk, 108840 Moscow, Russia;
| | - Alexander Sovetsky
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Uljanova Street, 603950 Nizhny Novgorod, Russia; (A.S.); (A.M.); (L.M.); (V.Z.)
| | - Alexander Matveyev
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Uljanova Street, 603950 Nizhny Novgorod, Russia; (A.S.); (A.M.); (L.M.); (V.Z.)
| | - Lev Matveev
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Uljanova Street, 603950 Nizhny Novgorod, Russia; (A.S.); (A.M.); (L.M.); (V.Z.)
| | - Emil Sobol
- UCI Health Beckman Laser Institute & Medical Clinic, 1002 Health Sciences Rd., Irvine, CA 92612, USA;
| | - Vladimir Zaitsev
- Institute of Applied Physics of the Russian Academy of Sciences, 46 Uljanova Street, 603950 Nizhny Novgorod, Russia; (A.S.); (A.M.); (L.M.); (V.Z.)
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7
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Matveyev AL, Matveev LA, Moiseev AA, Sovetsky AA, Gelikonov GV, Zaitsev VY. Simulating scan formation in multimodal optical coherence tomography: angular-spectrum formulation based on ballistic scattering of arbitrary-form beams. BIOMEDICAL OPTICS EXPRESS 2021; 12:7599-7615. [PMID: 35003855 PMCID: PMC8713662 DOI: 10.1364/boe.440739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 06/14/2023]
Abstract
We present a computationally highly efficient full-wave spectral model of OCT-scan formation with the following features: allowance of arbitrary phase-amplitude profile of illuminating beams; absence of paraxial approximation; utilization of broadly used approximation of ballistic scattering by discrete scatterers without limitations on their density/location and scattering strength. The model can easily incorporate the wave decay, dispersion, measurement noises with given signal-to-noise ratios and arbitrary inter-scan displacements of scatterers. We illustrate several of such abilities, including comparative simulations of OCT-scans for Bessel versus Gaussian beams, presence of arbitrary aberrations at the tissue boundary and various scatterer motions. The model flexibility and computational efficiency allow one to accurately study various properties of OCT-scans for developing new methods of their processing in various biomedical applications.
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Affiliation(s)
- Alexander L. Matveyev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Lev A. Matveev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Aleksandr A. Moiseev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Alexander A. Sovetsky
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Grigory V. Gelikonov
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Vladimir Y. Zaitsev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
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8
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Zaitsev VY, Matveyev AL, Matveev LA, Sovetsky AA, Hepburn MS, Mowla A, Kennedy BF. Strain and elasticity imaging in compression optical coherence elastography: The two-decade perspective and recent advances. JOURNAL OF BIOPHOTONICS 2021; 14:e202000257. [PMID: 32749033 DOI: 10.1002/jbio.202000257] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 05/20/2023]
Abstract
Quantitative mapping of deformation and elasticity in optical coherence tomography has attracted much attention of researchers during the last two decades. However, despite intense effort it took ~15 years to demonstrate optical coherence elastography (OCE) as a practically useful technique. Similarly to medical ultrasound, where elastography was first realized using the quasi-static compression principle and later shear-wave-based systems were developed, in OCE these two approaches also developed in parallel. However, although the compression OCE (C-OCE) was proposed historically earlier in the seminal paper by J. Schmitt in 1998, breakthroughs in quantitative mapping of genuine local strains and the Young's modulus in C-OCE have been reported only recently and have not yet obtained sufficient attention in reviews. In this overview, we focus on underlying principles of C-OCE; discuss various practical challenges in its realization and present examples of biomedical applications of C-OCE. The figure demonstrates OCE-visualization of complex transient strains in a corneal sample heated by an infrared laser beam.
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Affiliation(s)
- Vladimir Y Zaitsev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander L Matveyev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Lev A Matveev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander A Sovetsky
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Matt S Hepburn
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, Western Australia, Australia
| | - Alireza Mowla
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, Western Australia, Australia
| | - Brendan F Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, 6009, Australia and Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, Western Australia, Australia
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9
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Kazaili A, Lawman S, Geraghty B, Eliasy A, Zheng Y, Shen Y, Akhtar R. Line-Field Optical Coherence Tomography as a tool for In vitro characterization of corneal biomechanics under physiological pressures. Sci Rep 2019; 9:6321. [PMID: 31004101 PMCID: PMC6474860 DOI: 10.1038/s41598-019-42789-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/03/2019] [Indexed: 12/02/2022] Open
Abstract
There has been a lot of interest in accurately characterising corneal biomechanical properties under intraocular pressure (IOP) to help better understand ocular pathologies that are associated with elevated IOP. This study investigates the novel use of Line-Field Optical Coherence Tomography (LF-OCT) as an elastographic tool for accurately measuring mechanical properties of porcine corneas based on volumetric deformation following varying IOPs. A custom-built LF-OCT was used to measure geometrical and corneal surface displacement changes in porcine corneas under a range of IOPs, from 0-60 mmHg. Corneal thickness, elastic properties and hysteresis were calculated as a function of pressure. In addition, the effects of hydration were explored. We found that the elastic modulus increased in a linear fashion with IOP. Corneal thickness was found to reduce with IOP, decreasing 14% from 0 to 60 mmHg. Prolonged hydration in phosphate buffered saline (PBS) was found to significantly increase the elastic modulus and corneal hysteresis. Our study demonstrates that LF-OCT can be used to accurately measure the elastic properties based on volumetric deformation following physiological pressures. Furthermore, we show that prolonged hydration in PBS has a significant effect on the measured corneal properties.
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Affiliation(s)
- Ahmed Kazaili
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
- Department of Biomedical Engineering, College of Engineering, University of Babylon, Hillah, Iraq
| | - Samuel Lawman
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Brendan Geraghty
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Ashkan Eliasy
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Yalin Zheng
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Yaochun Shen
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Riaz Akhtar
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK.
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10
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Zaitsev VY, Matveyev AL, Matveev LA, Gelikonov GV, Baum OI, Omelchenko AI, Shabanov DV, Sovetsky AA, Yuzhakov AV, Fedorov AA, Siplivy VI, Bolshunov AV, Sobol EN. Revealing structural modifications in thermomechanical reshaping of collagenous tissues using optical coherence elastography. JOURNAL OF BIOPHOTONICS 2019; 12:e201800250. [PMID: 30417604 DOI: 10.1002/jbio.201800250] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/06/2018] [Accepted: 11/06/2018] [Indexed: 05/20/2023]
Abstract
Moderate heating of such collagenous tissues as cornea and cartilages by infra-red laser (IR laser) irradiation is an emerging technology for nondestructive modification of the tissue shape and microstructure for a variety of applications in ophthalmology, otolaryngology and so on. Postirradiation high-resolution microscopic examination indicates the appearance of microscopic either spheroidal or crack-like narrow pores depending on the tissue type and irradiation regime. Such examinations usually require special tissue preparation (eg, staining, drying that affect microstructure themselves) and are mostly suitable for studying individual pores, whereas evaluation of their averaged parameters, especially in situ, is challenging. Here, we demonstrate the ability of optical coherence tomography (OCT) to visualize areas of pore initiation and evaluate their averaged properties by combining visualization of residual irradiation-induced tissue dilatation and evaluation of the accompanying Young-modulus reduction by OCT-based compressional elastography. We show that the averaged OCT-based data obtained in situ fairly well agree with the microscopic examination results. The results obtained develop the basis for effective and safe applications of novel nondestructive laser technologies of tissue modification in clinical practice. PICTURE: Elastographic OCT-based images of an excised rabbit eye cornea subjected to thermomechanical laser-assisted reshaping. Central panel shows resultant cumulative dilatation in cornea after moderate (~45-50°C) pulse-periodic heating by an IR laser together with distribution of the inverse Young modulus 1/E before (left) and after (right) IR irradiation. Significant modulus decrease in the center of irradiated region is caused by initiated micropores. Their parameters can be extracted by analyzing the elastographic images.
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Affiliation(s)
- Vladimir Y Zaitsev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander L Matveyev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Lev A Matveev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Grigory V Gelikonov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Olga I Baum
- Institute of Photon Technologies, Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Moscow, Russia
| | - Alexander I Omelchenko
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
- Institute of Photon Technologies, Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Moscow, Russia
| | - Dmitry V Shabanov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander A Sovetsky
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexey V Yuzhakov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
- Institute of Photon Technologies, Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Moscow, Russia
| | | | | | | | - Emil N Sobol
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
- Institute of Photon Technologies, Federal Scientific Research Centre "Crystallography and Photonics", Russian Academy of Sciences, Moscow, Russia
- IPG Medical Corporation, Marlborough, Massachusetts
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