Assessment of corneal biomechanical properties and their variation with age

Ahmed Elsheikh, Defu Wang, Michael Brown, Paolo Rama, Marino Campanelli, David Pye

    Research output: Contribution to journalArticlepeer-review

    327 Citations (Scopus)


    The aim of this study was to determine the stress-strain behavior of corneal tissue and how the behavior was affected by age. Methods: Human corneal specimens ranging in age between 50 and 95 years were tested under inflation conditions to determine their stress-strain behavior. The corneas were subjected to two load rates that represent dynamic and static loading conditions. The pressure-deformation results were analyzed using shell theory to derive the stress-strain behavior. Results: The corneas demonstrated clear nonlinear behavior with an initial low stiffness stage and a final high stiffness stage. The transition between the two stages coincided with intraocular pressures between 12 and 20 mmHg. There was a considerable increase in stiffness associated with both age and load rate. Equations were derived to describe the nonlinear stress-strain relationship of corneal tissue for any age between 50 and 95 years, and these equations are presented in a form suitable for use in numerical simulations. Conclusions: The cornea demonstrates considerable stiffening with age with the behavior closely fitting an exponential power function typical of collagenous tissue. The increase in stiffness could be related to the additional age-related nonenzymatic cross-linking affecting the stromal collagen fibrils.
    Original languageEnglish
    Pages (from-to)11-19
    Number of pages9
    JournalCurrent Eye Research
    Issue number1
    Publication statusPublished - 2007


    • Aging
    • Ocular biomechanics
    • Stress-strain behavior


    Dive into the research topics of 'Assessment of corneal biomechanical properties and their variation with age'. Together they form a unique fingerprint.

    Cite this