Mechanics of nonlinear biomembranes: application to ophthalmology

Abstract

Changes in the mechanics of the lens capsule of the eye arising from alterations of its native configuration can lead to undesirable clinical results. One example is the surgical introduction of a hole into the lens capsule and subsequent removal of the cloudy lens during cataract surgery. The adverse effect is secondary cataract on the posterior lens capsule, brought about by a sudden proliferation of lens epithelial cells in the region. Understanding the biomechanics of the anterior lens capsule is necessary in order to model its behavior under various physiological conditions and predict its response to alterations and perturbations such as those during cataract surgery. Such knowledge will help in the improvement of techniques during cataract surgery, and in the design of artificial intraocular lens. In this study we present, for the first time, results that demonstrate that the anterior lens capsule exhibits non-homogeneity and regionally varying anisotropy. We also compute stresses in the lens capsule due to normal loading conditions and procedures such as a capsulorhexis.