Research Paper Volume 11, Issue 24 pp 12497—12531
Age-related changes in eye lens biomechanics, morphology, refractive index and transparency
- 1 School of Optometry, Indiana University, Bloomington, IN 47405, USA
- 2 Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
- 3 Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- 4 Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA 30303, USA
- 5 School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
- 6 Japan Synchrotron Radiation Research Institute (Spring-8), Sayo-cho, Sayo-gun, Hyogo, Japan
- 7 Department of Radiology, Boston University School of Medicine, Boston, MA 02118, USA
Received: August 30, 2019 Accepted: November 26, 2019 Published: December 16, 2019
https://doi.org/10.18632/aging.102584How to Cite
Copyright © 2019 Cheng et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Life-long eye lens function requires an appropriate gradient refractive index, biomechanical integrity and transparency. We conducted an extensive study of wild-type mouse lenses 1-30 months of age to define common age-related changes. Biomechanical testing and morphometrics revealed an increase in lens volume and stiffness with age. Lens capsule thickness and peripheral fiber cell widths increased between 2 to 4 months of age but not further, and thus, cannot account for significant age-dependent increases in lens stiffness after 4 months. In lenses from mice older than 12 months, we routinely observed cataracts due to changes in cell structure, with anterior cataracts due to incomplete suture closure and a cortical ring cataract corresponding to a zone of compaction in cortical lens fiber cells. Refractive index measurements showed a rapid growth in peak refractive index between 1 to 6 months of age, and the area of highest refractive index is correlated with increases in lens nucleus size with age. These data provide a comprehensive overview of age-related changes in murine lenses, including lens size, stiffness, nuclear fraction, refractive index, transparency, capsule thickness and cell structure. Our results suggest similarities between murine and primate lenses and provide a baseline for future lens aging studies.