Interplay between corneal oxygenation and swelling for scleral lens–a modelling approach

• 2-D Modelling of corneal oxygenation as a tool for predicting the cornea swelling. • The model takes into account of the coupling between the oxygen transfer and the corneal metabolism. • The lens decentring, that causes a reduction of oxygen rate is investigating using the 2-D model. • The parameters included in the model are determined using experimental measurements (using OCT technology). In this study, a mathematical model was developed that incorporates a coupling between mass transfer and corneal metabolism to predict corneal oxygenation with scleral lenses. The implementation of lens wear was achieved through the use of two distinct 2D geometries, each characterized by a unique central clearance (271 µm and 573 µm, respectively), as measured by means of OCT technology. The variation in tear film (also called tear reservoir) thickness in conjunction with the lens was found to induce a shift in corneal metabolism from the aerobic to the anaerobic pathway. This shift in oxygen transfer rate to the cornea is predicted to result in local corneal swelling. The numerical model demonstrated that enhancing lens permeability leads to an increase in corneal oxygenation; however, this gain is constrained by the tear reservoir's oxygen transfer resistance. Furthermore, with lens decentration, oxygenation exhibited an increase in the upper part of the cornea, while it decreased in the lower part, owing to the tear reservoir thickness variation with lens decentration. However, the oxygen demand and the tear reservoir thickness at the central part of the cornea exhibited only very small variation with decentration.