March 2012
Volume 53, Issue 14
Free
ARVO Annual Meeting Abstract  |   March 2012
Automated Measurement of Corneal Stromal Collagen Fiber Angular Distribution
Author Affiliations & Notes
  • Moritz Winkler
    Ophthalmology, University of California, Irvine, Irvine, California
  • Krystel R. Huxlin
    Flaum Eye Institute, University of Rochester, Rochester, New York
  • Christopher J. Murphy
    Surgical Radiol Sci-Sch of Veterinary, Univ of California-Davis, Davis, California
  • Donald J. Brown
    Ophthalmology, University of California, Irvine, Irvine, California
  • James V. Jester
    Ophthalmology, University of California, Irvine, Irvine, California
  • Footnotes
    Commercial Relationships  Moritz Winkler, None; Krystel R. Huxlin, None; Christopher J. Murphy, None; Donald J. Brown, None; James V. Jester, None
  • Footnotes
    Support  NIH Grant EY018665, Research to Prevent Blindness Inc, Discovery Eye Foundation, Skirball Program in Molecular Ophthalmology
Investigative Ophthalmology & Visual Science March 2012, Vol.53, 6792. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Moritz Winkler, Krystel R. Huxlin, Christopher J. Murphy, Donald J. Brown, James V. Jester; Automated Measurement of Corneal Stromal Collagen Fiber Angular Distribution. Invest. Ophthalmol. Vis. Sci. 2012;53(14):6792.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : 3-Dimensional reconstructions of non-linear optical (NLO), second harmonic generated signals using high resolution macroscopy (HRMac) have shown that the anterior stroma of the human cornea contains a diverse population of bow-spring and intertwined collagen fibers that generally run transverse to the corneal surface and insert into the anterior limiting lamina (Bowman’s layer). We have hypothesized that these collagen fibers play an important role in controlling corneal biomechanical properties shape. The purpose of this study was to develop an automated and objective approach to quantify the angular distribution of collagen fibers in the corneal stroma on a large scale, which will allow investigation of the relationship between local shape and fiber angle in isolated human corneas and corneas of different species.

Methods: : Human and animal corneas were fixed in 4% paraformaldehyde and cut into 250 µm sagittal cross-sections spanning the full corneal diameter using a vibratome. Sections were scanned from limbus to limbus using NLO-HRMac as previously described. An automated script based on algorithms by Rezakhaniha et al was developed to determine fiber angle relative to local corneal curvature at 10 µm steps along the full thickness of the cornea. Angles and their variance were tracked as a function of stromal depth and compared to fiber interconnectivity and structural data.

Results: : Fiber angles relative to the corneal surface decreased markedly with increasing stromal depth. Fiber angle variance in the human cornea was high in the anterior stroma and approached zero at 350 µm or 2/3 the depth from the anterior surface. In the cat cornea, fiber angle variance in the anterior cornea appeared similar to that of the human, but reached zero at 1/3 depth.

Conclusions: : This approach generates verifiable angular distribution data consistent with corresponding SHG images and previously published measurements of fiber interconnectivity. Overall, the data indicate that there are species differences in the contribution of angled stromal collagen fibers that may be associated with differences in corneal shape and elasticity. Future studies comparing shape and 3-D fiber angle distribution may provide insight into the biomechanical mechanisms controlling corneal shape and refractive errors.

Keywords: cornea: stroma and keratocytes • extracellular matrix • image processing 
×
×

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.

×