Effect of freezing on lens capsule mechanical behavior.

Postmortem storage of lens capsules by freezing was found to increase capsular thickness slightly (5%). The effect on mechanical properties was minor. Ultimate tensile strength and ultimate stiffness were not changed by freezing. Ultimate strain was slightly increased (2%) and the elastic modulus calculated at 40% strain was decreased (20%). Frozen capsules were found to relax to a slightly lower value than fresh ones (2%). The results show that freezing tends to soften the tissue, possibly due to an increased hydration. In spite of this effect, which has to be kept in mind, postmortem freezing seems to be an acceptable storage method when collecting tissue for biomechanical research.