May 2007
Volume 48, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2007
The Measurement of Biomechanical Parameters as a Function of Peak Applied Pressure in the Reichert Ocular Response Analyzer
Author Affiliations & Notes
  • E. J. Rouse
    The Ohio State University, Columbus, Ohio
    College of Engineering,
  • C. J. Roberts
    The Ohio State University, Columbus, Ohio
    Biomedical Engineering,
    Ophthalmology,
  • A. M. Mahmoud
    The Ohio State University, Columbus, Ohio
    Biomedical Engineering,
    Ophthalmology,
  • Footnotes
    Commercial Relationships E.J. Rouse, None; C.J. Roberts, Reichert, C; Reichert, R; A.M. Mahmoud, None.
  • Footnotes
    Support None.
Investigative Ophthalmology & Visual Science May 2007, Vol.48, 1247. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      E. J. Rouse, C. J. Roberts, A. M. Mahmoud; The Measurement of Biomechanical Parameters as a Function of Peak Applied Pressure in the Reichert Ocular Response Analyzer. Invest. Ophthalmol. Vis. Sci. 2007;48(13):1247. doi: https://doi.org/.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose:: To determine if the biomechanical parameters measured by the Ocular Response Analyzer (ORA) are a function of the characteristics of the applied air pressure curve.

Methods:: The setup consisted of a commercial ORA with custom software to allow the peak applied air pressure to be manipulated through a graphical user interface created in Matlab. Preliminary testing on 6 eyes was preformed with the ORA at 6 different maximum pressure levels. Each trial involved 3 replicate measurements at each of the programmed maximum pressure values. One trial was taken at each maximum pressure of 500, 400, 300, 200 and 100 arbitrary units. The infrared applanation signal data and air pressure data were stored each corresponding to a specific time value, as well as the output parameters of corneal hysteresis (CH), corneal resistance factor (CRF), and corneal compensated intraocular pressure (IOPcc). Both linear and quadratic regressions were performed on the data from each of the 6 eyes to determine the nature of the relationship between peak air pressure and biomechanical parameter measurement. The R2 values of the linear and quadratic regressions were statistically compared to determine the best-fit.

Results:: The comparison of R2 values showed a statistically significant (p<0.05) better fit with a quadratic regression, when compared to linear regression analysis. The nonlinear response of CH and CRF was characterized by a linear increase with increasing peak pressure over the lower range of pressures, which leveled off at the higher peak applied pressures. IOPcc demonstrated an opposite relationship with a decreasing function of peak applied pressure in the lower ranges.

Conclusions:: Corneal viscoelastic response is a function of the rate of force application. The current study demonstrates a nonlinear response of the measured parameters as peak pressure is varied. Clinically, it is important that the peak applied pressure is in the higher range to assure that CH, CRF, and IOPcc values are stable.

Keywords: intraocular pressure • cornea: basic science • cornea: clinical science 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×