Nearly-incompressible transverse isotropy (NITI) of cornea elasticity: model and experiments with acoustic micro-tapping OCE
| Autor: | Matthew O'Donnell, Ivan Pelivanov, Tueng T. Shen, Ruikang K. Wang, John J. Pitre, David S. Li, Mitchell A. Kirby |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Keratoconus
Intraocular pressure Shear waves Materials science genetic structures Swine Corneal diseases Science Models Biological 01 natural sciences Article Cornea 010309 optics 03 medical and health sciences 0302 clinical medicine Transverse isotropy 0103 physical sciences Ultimate tensile strength medicine Animals Humans Elasticity (economics) Multidisciplinary Imaging and sensing Stiffness Acoustics medicine.disease Elasticity eye diseases medicine.anatomical_structure 030221 ophthalmology & optometry Elasticity Imaging Techniques Medicine Medical imaging sense organs medicine.symptom Biological physics Biomedical engineering |
| Zdroj: | Scientific Reports, Vol 10, Iss 1, Pp 1-14 (2020) Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | The cornea provides the largest refractive power for the human visual system. Its stiffness, along with intraocular pressure (IOP), are linked to several pathologies, including keratoconus and glaucoma. Although mechanical tests can quantify corneal elasticity ex vivo, they cannot be used clinically. Dynamic optical coherence elastography (OCE), which launches and tracks shear waves to estimate stiffness, provides an attractive non-contact probe of corneal elasticity. To date, however, OCE studies report corneal moduli around tens of kPa, orders-of-magnitude less than those (few MPa) obtained by tensile/inflation testing. This large discrepancy impedes OCE’s clinical adoption. Based on corneal microstructure, we introduce and fully characterize a nearly-incompressible transversely isotropic (NITI) model depicting corneal biomechanics. We show that the cornea must be described by at least two shear moduli, contrary to current single-modulus models, decoupling tensile and shear responses. We measure both as a function of IOP in ex vivo porcine cornea, obtaining values consistent with both tensile and shear tests. At pressures above 30 mmHg, the model begins to fail, consistent with non-linear changes in cornea at high IOP. |
| Databáze: | OpenAIRE |
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