Parameter estimation for evaporation-driven tear film model in two space dimensions

TL;DR

This study estimates key physical parameters of tear film evaporation and thinning using a two-dimensional PDE model fitted to fluorescence imaging data, improving understanding of dry eye mechanisms.

Contribution

It extends a PDE-based tear film model to two dimensions with dimension reduction, enabling efficient parameter estimation from in vivo imaging data.

Findings

Provided in vivo estimates of evaporation and thinning parameters.

Enhanced understanding of tear film thinning and dry-spot formation.

Established a baseline for comparing healthy and dry eye conditions.

Abstract

The tear film (TF) plays a critical role in maintaining ocular surface health, and its disruption through tear breakup (TBU) is closely associated with dry eye disease. Evaporation-driven thinning is a primary mechanism underlying TBU, yet quantitative in vivo estimates of key physical parameters remain limited. In this work, we fit an evaporation-driven TF thinning model, originally developed by Braun et al. and extended to two dimensions using proper orthogonal decomposition (POD) by Chen et al., to experimental fluorescence (FL) imaging data from normal subjects. The use of dimension reduction enables efficient solution of the governing PDEs and facilitates parameter estimation from imaging data. Our results provide in vivo estimates of evaporation-related and thinning parameters within TBU regions. These findings enhance understanding of TF thinning and dry-spot formation and establish a quantitative baseline for comparison with dry eye patient data.