Constructal approach to bio-engineering: the ocular anterior chamber temperature

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

The aim of this work was to analyse the pressure inside the eyes anterior chamber, namedintraocular pressure (IOP), in relation to the biomechanical properties of corneas. The approach used was based on the constructal law, recently introduced in vision analysis. Results were expressed as the relation between the temperature of the ocular anterior chamber and the biomechanical properties of the cornea. The IOP, the elastic properties of the cornea, and the related refractive properties of the eye were demonstrated to be dependent on the temperature of the ocular anterior chamber. These results could lead to new perspectives for experimental analysis of the IOP in relation to the properties of the cornea.

Related collections

Most cited references 15

Record: found
Abstract: found
Article: not found

Strip extensiometry for comparison of the mechanical response of bovine, rabbit, and human corneas.

P Altman, D Hoeltzel, Y-K Choe … (1992)

Specimens of bovine, rabbit, and human corneas were systematically tested in uniaxial tension to experimentally determine their effective nonlinear stress-strain relations, and hysteresis. Cyclic tensile tests were performed over the physiologic load range of the cornea, up to a maximum of 10 percent strain beyond slack strain. Dimensional changes to corneal test specimens, due to varying laboratory environmental conditions, were also assessed. The measured stress-strain data was found to closely fit exponential power function relations typical of collagenous tissues when appropriate account was taken of specimen slack strain. These constitutive relations are very similar for rabbit, human and bovine corneas; there was no significant difference between the species after preconditioning by one cycle. The uniaxial stress strain curves for all species behave similarly in that their tangent moduli increase at high loads and decrease at low loads as a function of cycling. In the bovine and rabbit data, there is a general trend towards more elastic behavior from the first to second cycles, but there is little variation in these parameters from the second to third cycles. In comparison, the human data demonstrates relatively little change between cycles. Increases in width of corneal test specimens, up to a maximum of 2 percent were found to occur under 95 percent relative humidity test conditions over 10 minutes elapsed time test periods, while specimens which were exposed to normal laboratory conditions (45 percent RH) were found to shrink in width up to a maximum of 9.5 percent over the same elapsed time period. The thickness of the test specimens were observed to decrease by 3 percent in 95 percent relative humidity and by 12 percent in 45 percent relative humidity over the same elapsed time period.

0 comments Cited 42 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Relationship between central corneal thickness, refractive error, corneal curvature, anterior chamber depth and axial length.

Mei-Ju May Chen, Yin-Tzu Liu, Chia-Chen Tsai … (2009)

To determine the relationship between central corneal thickness (CCT), refractive error, corneal curvature, anterior chamber depth and axial length in normal Taiwanese Chinese adults. Five hundred normal Taiwanese Chinese patients aged 40-80 years were recruited for the study. Measurement procedures included CCT, refractive error, corneal curvature, anterior chamber depth and axial length. Exclusion criteria were previous ocular surgery, glaucoma, trauma history, external eye disease, and previous contact lens use. The relationships among parameters were tested using Pearson's correlation and linear regression analysis. The median CCT was 555 +/- 27 mum for males and 553 +/- 30 mum for females. Eyes with more myopic refractive error tended to have greater axial length (r = -0.645, p < 0.001). Eyes with axial elongation tended to have flatter cornea (r = -0.502, p < 0.001) and deeper anterior chamber (r = 0.651, p < 0.001). There were no significant correlations between the CCT and refractive error (r = -0.034, p = 0.445), corneal curvature (r = 0.013, p = 0.770), anterior chamber depth (r = 0.023, p = 0.614) and axial length (r = -0.053, p = 0.223). CCT was not associated with refractive error, corneal curvature, anterior chamber depth and axial length. CCT is an independent factor unrelated to other ocular parameters.

0 comments Cited 37 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: found

Is Open Access

Why the bigger live longer and travel farther: animals, vehicles, rivers and the winds

Adrian Bejan (2012)

Here we show that constructal-law physics unifies the design of animate and inanimate movement by requiring that larger bodies move farther, and their movement on the landscape last longer. The life span of mammals must scale as the body mass (M) raised to the power 1/4, and the distance traveled during the lifetime must increase with body size. The same size effect on life span and distance traveled holds for the other flows that move mass on earth: atmospheric and oceanic jets and plumes, river basins, animals and human operated vehicles. The physics is the same for all flow systems on the landscape: the scaling rules of “design” are expressions of the natural tendency of all flow systems to generate designs that facilitate flow access. This natural tendency is the constructal law of design and evolution in nature. Larger bodies are more efficient movers of mass on the landscape.

0 comments Cited 31 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Sci Rep

Journal ID (iso-abbrev): Sci Rep

Title: Scientific Reports

Publisher: Nature Publishing Group

ISSN (Electronic): 2045-2322

Publication date (Electronic): 05 August 2016

Publication date Collection: 2016

Volume: 6

Electronic Location Identifier: 31099

Affiliations

[1 ]Dipartimento Energia, Politecnico di Torino , Corso Duca degli Abruzzi 24, 10129 Torino, Italy

[2 ]Dipartimento di Oculistica, Azienda Ospedaliera Nazionale SS. Antonio e Biagio e Cesare Arrigo , Via Venezia 7, 15121 Alessandria, Italy

[3 ]Dipartimento di Scienze Mediche, Università di Torino , Corso A.M. Dogliotti 14, 10126 Torino, Italy

Author notes

[a ] umberto.lucia@ 123456polito.it

Article

Publisher Item ID: srep31099

DOI: 10.1038/srep31099

PMC ID: 4974607

PubMed ID: 27492652

SO-VID: 6e4e15c7-ee7d-48f2-9469-c9e93ac28aee

License:

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Constructal approach to bio-engineering: the ocular anterior chamber temperature

Read this article at

Abstract

Related collections

BIO Integration

Most cited references 15

Strip extensiometry for comparison of the mechanical response of bovine, rabbit, and human corneas.

Relationship between central corneal thickness, refractive error, corneal curvature, anterior chamber depth and axial length.

Why the bigger live longer and travel farther: animals, vehicles, rivers and the winds

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 141

Cited by 4

Most referenced authors 87