Detecting Mechanical Anisotropy of the Cornea Using Brillouin Microscopy.
Transl Vis Sci Technol
; 9(7): 26, 2020 06.
Article
en En
| MEDLINE
| ID: mdl-32832232
ABSTRACT
Purpose:
The purpose of this study was to detect the mechanical anisotropy of the cornea using Brillouin microscopy along different perturbation directions.Methods:
Brillouin frequency shift of both whole globes (n = 10) and cornea punches (n = 10) were measured at different angles to the incident laser, thereby probing corneal longitudinal modulus of elasticity along different directions. Frequency shift of virgin (n = 26) versus cross-linked corneas (n = 15) over a large range of hydration conditions were compared in order to differentiate the contributions to Brillouin shift due to hydration from those due to stromal tissue.Results:
We detected mechanical anisotropy of corneas, with an average frequency shift increase of 53 MHz and 96 MHz when the instrument probed from 0° to 15° and 30° along the direction of the stromal fibers. Brillouin microscopy did not lose sensitivity to mechanical anisotropy up to 96% water content. We experimentally measured and theoretically modeled how mechanical changes independent of hydration affect frequency shift as a result of corneal cross-linking by isolating an approximately 100 MHz increase in frequency shift following a cross-linking procedure purely due to changes of stromal tissue mechanics.Conclusions:
Brillouin microscopy is sensitive to mechanical anisotropy of the stroma even in highly hydrated corneas. The agreement between model and experimental data suggested a quantitative relationship between Brillouin frequency shift, hydration state of the cornea, and stromal tissue stiffness. Translational Relevance The protocol and model validated throughout this study offer a path for comprehensive measurements of corneal mechanics within the clinic; allowing for improved evaluation of the long-term mechanical efficacy of cross-linking procedures.Palabras clave
Texto completo:
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Banco de datos:
MEDLINE
Asunto principal:
Córnea
/
Microscopía
Tipo de estudio:
Guideline
Idioma:
En
Revista:
Transl Vis Sci Technol
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos