A transient diffusion model of the cornea for the assessment of oxygen diffusivity and consumption.
OBJECTIVE
Oxygen diffusivity and consumption in the human cornea have not been directly measured yet; current models rely on properties measured in vitro in rabbit corneas. The aim of this study was to present a mathematical model of time-dependent oxygen diffusion that permits the estimation of corneal consumption and diffusivity.


METHODS
The current oxygen diffusion model was extended to include the temporal domain and was used to simulate in vivo noninvasive measurements of tear oxygen tension in human corneas.


RESULTS
The new model reproduced experimental data successfully, provided values for corneal diffusivity and consumption, and described the relationship between oxygen consumption and oxygen tension in the cornea. Estimated values were three times higher than those reported previously in in vitro rabbit experiments.


CONCLUSIONS
This model allowed for the further investigation of oxygen transport in the cornea, including a better mathematical description and a determination of the transport properties of the cornea and the specific oxygen uptake rate of the tissue. The combination of this model and tear oxygen tension measurements can be useful in determining the individual oxygen uptake rate and exploring the relationship between oxygen transport and corneal abnormalities.
Institute for Surgical Technology and Biomechanics, ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
Xabier
X
Larrea
Philippe
P
Büchler
D001692:Biological Transport; D003261:Contact Lenses; D003315:Cornea / Q000378:metabolism*; D004058:Diffusion; D006801:Humans; D008962:Models, Theoretical; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D013666:Tears / Q000378:metabolism; D013997:Time Factors
D010100:Oxygen