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Direct measurements of collagen fiber recruitment in the posterior pole of the eye
Collagen is the main load-bearing component of the peripapillary sclera (PPS) and lamina cribrosa (LC) in the eye. Whilst it has been shown that uncrimping and recruitment of the PPS and LC collagen fibers underlies the macro-scale nonlinear stiffening of both tissues with increased intraocular pres...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Cold Spring Harbor Laboratory
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10197604/ https://www.ncbi.nlm.nih.gov/pubmed/37215028 http://dx.doi.org/10.1101/2023.05.07.539784 |
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author | Lee, Po-Yi Fryc, Gosia Gnalian, John Hua, Yi Waxman, Susannah Zhong, Fuqiang Yang, Bin Sigal, Ian A |
author_facet | Lee, Po-Yi Fryc, Gosia Gnalian, John Hua, Yi Waxman, Susannah Zhong, Fuqiang Yang, Bin Sigal, Ian A |
author_sort | Lee, Po-Yi |
collection | PubMed |
description | Collagen is the main load-bearing component of the peripapillary sclera (PPS) and lamina cribrosa (LC) in the eye. Whilst it has been shown that uncrimping and recruitment of the PPS and LC collagen fibers underlies the macro-scale nonlinear stiffening of both tissues with increased intraocular pressure (IOP), the uncrimping and recruitment as a function of local stretch have not been directly measured. This knowledge is crucial for the development of constitutive models associating micro and macro scales. In this project we measured local stretch-induced collagen fiber bundle uncrimping and recruitment curves of the PPS and LC. Thin coronal samples of PPS and LC of sheep eyes were mounted and stretched biaxially quasi-statically using a custom system. At each step, we imaged the PPS and LC with instant polarized light microscopy and quantified pixel-level (1.5 μm/pixel) collagen fiber orientations. We used digital image correlation to measure the local stretch and quantified collagen crimp by the circular standard deviation of fiber orientations, or waviness. Local stretch-recruitment curves of PPS and LC approximated sigmoid functions. PPS recruited more fibers than the LC at the low levels of stretch. At 10% stretch the curves crossed with 75% bundles recruited. The PPS had higher uncrimping rate and waviness remaining after recruitment than the LC: 0.9° vs. 0.6° and 3.1° vs. 2.7°. Altogether our findings support describing fiber recruitment of both PPS and LC with sigmoid curves, with the PPS recruiting faster and at lower stretch than the LC, consistent with a stiffer tissue. |
format | Online Article Text |
id | pubmed-10197604 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Cold Spring Harbor Laboratory |
record_format | MEDLINE/PubMed |
spelling | pubmed-101976042023-05-20 Direct measurements of collagen fiber recruitment in the posterior pole of the eye Lee, Po-Yi Fryc, Gosia Gnalian, John Hua, Yi Waxman, Susannah Zhong, Fuqiang Yang, Bin Sigal, Ian A bioRxiv Article Collagen is the main load-bearing component of the peripapillary sclera (PPS) and lamina cribrosa (LC) in the eye. Whilst it has been shown that uncrimping and recruitment of the PPS and LC collagen fibers underlies the macro-scale nonlinear stiffening of both tissues with increased intraocular pressure (IOP), the uncrimping and recruitment as a function of local stretch have not been directly measured. This knowledge is crucial for the development of constitutive models associating micro and macro scales. In this project we measured local stretch-induced collagen fiber bundle uncrimping and recruitment curves of the PPS and LC. Thin coronal samples of PPS and LC of sheep eyes were mounted and stretched biaxially quasi-statically using a custom system. At each step, we imaged the PPS and LC with instant polarized light microscopy and quantified pixel-level (1.5 μm/pixel) collagen fiber orientations. We used digital image correlation to measure the local stretch and quantified collagen crimp by the circular standard deviation of fiber orientations, or waviness. Local stretch-recruitment curves of PPS and LC approximated sigmoid functions. PPS recruited more fibers than the LC at the low levels of stretch. At 10% stretch the curves crossed with 75% bundles recruited. The PPS had higher uncrimping rate and waviness remaining after recruitment than the LC: 0.9° vs. 0.6° and 3.1° vs. 2.7°. Altogether our findings support describing fiber recruitment of both PPS and LC with sigmoid curves, with the PPS recruiting faster and at lower stretch than the LC, consistent with a stiffer tissue. Cold Spring Harbor Laboratory 2023-05-08 /pmc/articles/PMC10197604/ /pubmed/37215028 http://dx.doi.org/10.1101/2023.05.07.539784 Text en https://creativecommons.org/licenses/by-nc/4.0/This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/) , which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator. |
spellingShingle | Article Lee, Po-Yi Fryc, Gosia Gnalian, John Hua, Yi Waxman, Susannah Zhong, Fuqiang Yang, Bin Sigal, Ian A Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title | Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title_full | Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title_fullStr | Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title_full_unstemmed | Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title_short | Direct measurements of collagen fiber recruitment in the posterior pole of the eye |
title_sort | direct measurements of collagen fiber recruitment in the posterior pole of the eye |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10197604/ https://www.ncbi.nlm.nih.gov/pubmed/37215028 http://dx.doi.org/10.1101/2023.05.07.539784 |
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