Biomechanics of Lens Morphogenesis

Project Summary Lens shape is a primary determinant of its optical power and accommodative ability. Growth-induced change in lens shape directly causes presbyopia and is a known risk factor for age-related cataract. However, the biomechanical factors which interact to govern age-related changes in lens shape remain unknown. In the proposed study, we will systematically characterize the biomechanical properties of the aging human lens and use that information to understand how the lens shape evolves with age. A novel theory of constrained soft tissue growth will be employed to account for the presence of the lens capsule and its influence on the volumetric expansion of the lens fiber cell compartment. The biomechanical interaction between the fiber cell compartment and the capsule ultimately dictates the shape of the lens. These interactions behave like a water balloon filled with gelatin: as the gelatin sets, the properties of the gelatin contribute more and more to the shape of the balloon.