Stromal striae: a new insight into corneal physiology and mechanics

Sci Rep. 2017 Oct 19;7(1):13584. doi: 10.1038/s41598-017-13194-6.

Abstract

We uncover the significance of a previously unappreciated structural feature in corneal stroma, important to its biomechanics. Vogt striae are a known clinical indicator of keratoconus, and consist of dark, vertical lines crossing the corneal depth. However we detected stromal striae in most corneas, not only keratoconus. We observed striae with multiple imaging modalities in 82% of 118 human corneas, with pathology-specific differences. Striae generally depart from anchor points at Descemet's membrane in the posterior stroma obliquely in a V-shape, whereas in keratoconus, striae depart vertically from posterior toward anterior stroma. Optical coherence tomography shear wave elastography showed discontinuity of rigidity, and second harmonic generation and scanning electron microscopies showed undulation of lamellae at striae locations. Striae visibility decreased beyond physiological pressure and increased beyond physiological hydration. Immunohistology revealed striae to predominantly contain collagen VI, lumican and keratocan. The role of these regions of collagen VI linking sets of lamellae may be to absorb increases in intraocular pressure and external shocks.

Publication types

  • Observational Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Biomechanical Phenomena
  • Collagen / analysis
  • Corneal Diseases / diagnostic imaging*
  • Corneal Diseases / pathology
  • Corneal Stroma / diagnostic imaging
  • Corneal Stroma / pathology*
  • Corneal Stroma / physiology*
  • Descemet Membrane
  • Elasticity Imaging Techniques / methods
  • Humans
  • Intraocular Pressure
  • Macaca
  • Mice
  • Microscopy, Electron, Scanning
  • Middle Aged
  • Prospective Studies
  • Tomography, Optical Coherence / methods

Substances

  • Collagen