title: Analysis of the application of the generalized monod kinetics model to describe the human corneal oxygen-consumption rate during soft contact lens wear.
abstract: This work is an analysis of the application of the generalized Monod kinetics model describing human corneal oxygen consumption during soft contact lens wear to models previously used by Chhabra et al. (J Biomed Mater Res B Appl Biomater, 2009a;90:202-209, Optom Vis Sci 2009b;86:454-466) and Larrea and Büchler (Invest Ophthalmol Vis Sci 2009;50:1076-1080). We use oxygen tension from in vivo estimations provided by Bonanno [Bonanno et al., Invest Ophthalmol Vis Sci 2002;43:371-376, and Bonanno et al 2009]. We consider four hydrogel and six silicone hydrogel lenses. The cornea is considered a single homogeneous layer, with constant oxygen permeability regardless of the type of lens worn. Our calculations yield different values for the maximum oxygen consumption rate Qc,max, whith differents oxygen tensions (high and low pc) at the cornea-tears interface. Surprisingly, for both models, we observe an increase in oxygen consumption near an oxygen tension of 105 mmHg until a maximum is reached, then decreasing for higher levels of oxygen pressure. That is, when lowering the pressure of oxygen, the parameter Qc,maxinitially increases depending on the intensity of the change in pressure. Which, it could be related with the variation of the pH. Furthermore, it is also noted that to greater reductions in pressure, this parameter decreases, possibly due to changes in the concentration of glucose related to the anaerobic respiration. The averaged in vivo human corneal oxygen consumption rate of 1.47 × 10-4cm3of O2/cm3tissue s, with Monod kinetics model, considering all the lenses studied, is smaller than the average oxygen consumption rate value obtained using the Larrea and Büchler model. The impact that these calculations have on the oxygen partial pressure available at different depths in the corneal tissue is presented and discussed, taking into consideration previous models used in this study. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2269-2281, 2017.
authors.affiliation: Departamento de Termodinámica Aplicada, Escuela Técnica Superior de Ingenieros Industriales (ETSII), Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Compañ
authors.affiliation: Departamento de Física aplicada, Universitat Jaume I, Castellón, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Aguilella-Arzo
authors.affiliation: Departamento de Polímeros, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Coyoacán, México, DF.
authors.forename: L F
authors.initials: LF
authors.lastname: Del Castillo
authors.affiliation: Unidad Multidiscliplinaria de Docencia e Investigación-Juriquilla, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Juriquilla, Querétaro, México.
authors.forename: S I
authors.initials: SI
authors.lastname: Hernández
authors.affiliation: Clinical & Experimental Optometry Research Lab, Center of Physics (Optometry), School of Sciences, University of Minho, Braga, Portugal.
authors.forename: J M
authors.initials: JM
authors.lastname: Gonzalez-Meijome
mesh_terms: D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010539:Permeability
chemical_list: D010100:Oxygen
keywords: Monod kinetics model; cornea; oxygen consumption; oxygen tension; soft contact lenses