Numerical simulation and analysis of the temporal concentration of timolol after topical administration in the human eye

Abstract

The temporal distribution of drugs in the eye tissues after the topical dosing is required to study the efficacy of the drugs. Glaucoma is one of the primary causes of vision impairment around the world and timolol is used in the treatment of glaucoma in general. This paper contributes to developing a model to represent the more accurate biophysics of the human eye through the finite element method compared to other state-of-the-art simulation models. A 2D human-eye model is used to simulate the temporal distribution of timolol after topical dosing within the COMSOL Multiphysics environment. The biophysics of the human eye including temperature regulation, fluid flow in the anterior segment, convection, diffusion, reaction kinetics of timolol, and metabolic consumption are incorporated in the proposed simulation model. The temporal concentration of timolol is analyzed for seven ocular tissues (cornea, iris, sclera, aqueous humor, lens, ciliary body, and trabecular meshwork) in this work. The peak concentration of timolol takes place within 2500 s in the ocular tissues considered in the simulation and the peak in the anterior chamber is observed at 1150 s. The comparison based on the normalized concentration of timolol in the anterior chamber demonstrates that the results of the proposed ocular model comply close with the practical findings. The mean difference with the experimental results is lower in this study compared to the recent numerical works on timolol. The proposed model can be used for analyzing the physiological behavior of human eyes under different types of drug delivery with varying initial concentrations.

Keywords

• Human-eye
• Concentration
• Timolol
• Diffusion
• Convection
• Numerical simulation