July 2020
Volume 61, Issue 9
Free
ARVO Imaging in the Eye Conference Abstract  |   July 2020
Non-contact in vivo corneal microscopy with asymmetric fundus retroillumination
Author Affiliations & Notes
  • Timothy D Weber
    Biomedical Engineering, Boston University, Boston, Massachusetts, United States
  • Jerome Mertz
    Biomedical Engineering, Boston University, Boston, Massachusetts, United States
  • Footnotes
    Commercial Relationships   Timothy Weber, None; Jerome Mertz, None
  • Footnotes
    Support  NIH Grant EY029486
Investigative Ophthalmology & Visual Science July 2020, Vol.61, PP005. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Timothy D Weber, Jerome Mertz; Non-contact in vivo corneal microscopy with asymmetric fundus retroillumination. Invest. Ophthalmol. Vis. Sci. 2020;61(9):PP005.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose : Cellular-resolution corneal imaging is a useful tool for noninvasive disease diagnostics and treatment monitoring. Still many subjects cannot tolerate the usual contact operation (i.e. the objective lens is placed in contact with the cornea), and this has fueled recent interest in non-contact alternatives. Existing techniques are all based on reflected light and therefore require a high degree of optical sectioning in order to reject much stronger reflections originating at other surfaces, such as the air-cornea interface. Here we present an alternative approach based on obliquely transmitted light, which produces phase-gradient contrast images of the cornea across a 1-mm field of view.

Methods : Our method, shown conceptually in Figure 1(A), uses reflected light from the fundus to transilluminate the cornea. We project the light on the fundus such that the reflected light obliquely back-illuminates the cornea. Asymmetric illumination is a simple way to convert phase-only objects (like the cornea) into intensity contrast, recordable on a camera. We call this method asymmetric fundus retroillumination microscopy, in homage to the related slit lamp technique. A detailed optical diagram is also given in Figure 1(B).

Results : We imaged 3 healthy volunteers ranging in age from 26 to 58 and with varying fundus pigmentation. For each subject, informed consent was obtained prior to imaging. The research was approved by the Boston University Institutional Review Board and conformed to the principles stated in the Declaration of Helsinki. Figure 2 shows a few example images that we have obtained with the retroillumination microscope. We can routinely image layers of cells in the epithelium, the sub-basal nerve plexus, large stromal nerves, and the endothelium. Additionally, we have imaged the crystalline lens epithelium and anterior fibers.

Conclusions : We have introduced a new technique for corneal microscopy based on fundus reflection. The technique is based on relatively inexpensive instrumentation and unlike other techniques, our method uses transmitted light, which produces different, but complimentary image contrast.

This is a 2020 Imaging in the Eye Conference abstract.

 

A: corneal retroillumination microscopy concept. B: detailed system schematic.

A: corneal retroillumination microscopy concept. B: detailed system schematic.

 

A: sub-basal nerve plexus, B: basal epithelial cell layer, C: dendritic immune cells, D: large stromal nerve, E: endothelium, nuclei are visible. Scale bars: 50 um.

A: sub-basal nerve plexus, B: basal epithelial cell layer, C: dendritic immune cells, D: large stromal nerve, E: endothelium, nuclei are visible. Scale bars: 50 um.

×
×

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.

×