April 2009
Volume 50, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2009
Validation of Posterior Cornea Quantitative Scheimpflug Imaging Using a Hybrid Porcine/Plastic Model
Author Affiliations & Notes
  • L. Remon
    Instituto de Optica, Consejo Superior de Invest Cientificas, Madrid, Spain
  • C. Dorronsoro
    Instituto de Optica, Consejo Superior de Invest Cientificas, Madrid, Spain
  • S. Kling
    Instituto de Optica, Consejo Superior de Invest Cientificas, Madrid, Spain
  • J. Merayo-LLoves
    Instituto de Oftalmobiología Aplicada, Universidad de Valladolid, Valladolid, Spain
  • S. Marcos
    Instituto de Optica, Consejo Superior de Invest Cientificas, Madrid, Spain
  • Footnotes
    Commercial Relationships  L. Remon, None; C. Dorronsoro, None; S. Kling, None; J. Merayo-LLoves, None; S. Marcos, None.
  • Footnotes
    Support  EURYI-05-102-ES and FIS2008-02065 to SM; CSIC JAE –TEC to LR. Erasmus internship to SK
Investigative Ophthalmology & Visual Science April 2009, Vol.50, 5105. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      L. Remon, C. Dorronsoro, S. Kling, J. Merayo-LLoves, S. Marcos; Validation of Posterior Cornea Quantitative Scheimpflug Imaging Using a Hybrid Porcine/Plastic Model. Invest. Ophthalmol. Vis. Sci. 2009;50(13):5105.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : Quantitative analysis of posterior corneal Scheimpflug images requires proper correction of geometrical and optical distortion from the anterior surfaces. We developed a hybrid porcine/plastic eye model (with the scattering properties and refractive index of corneal tissue and known posterior corneal geometry) for validation of the posterior corneal reconstruction of the Pentacam Scheimpflug imaging system.

Methods: : The hybrid porcine/plastic eye models consisted on excised porcine corneas mounted on a 12-mm diameter plastic piston finished on spherical surfaces with known radii of curvature (7.47, 7.93 and 8.75 mm, as validated by non-contact profilometry). Special care was taken to preserve the endothelium integrity. The porcine’s posterior cornea conformed to the underlying plastic surface. Scheimpflug images were obtained within 4 hours post-mortem. The posterior corneal surface was evaluated using both fitting routines written in Matlab and Pentacam software. We used 10 porcine corneas (5 repeated measurements per eye). The retrieved posterior corneal geometry was compared to the plastic surfaces’ nominal data. Correlations between anterior and posterior corneal data were performed to assess that the optical distortion correction was successfully applied.

Results: : There was a good correspondence between nominal and estimated posterior radii of curvature, although the measured radius was a consistently underestimated (0.26±0.12 mm on average). There was larger variability and underestimation of the posterior surface asphericity (Qpost=-0.33±0.44) than of the same spherical surfaces tested anteriorly (Qant=-0.02±0.22). The anterior porcine corneas varied in anterior radii (from 8.0 to 9.6) and astigmatism (1.9 ±1.0 D). However, there was no significant correlation between anterior and posterior corneal radii of curvature, asphericity or astigmatism (p>0.6).

Conclusions: : This model has allowed testing the accuracy of the posterior corneal geometry estimates from Pentacam. The independence of the retrieved data from the anterior corneal topography suggests proper correction of optical distortion. This model shows more comparable properties to those of living eyes and could be used for calibration of other anterior segment imaging systems.

Keywords: anterior segment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • topography 
×
×

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.

×