High-resolution three-dimensional Gabor-domain optical coherence microscopy for corneal tissue evaluation

Abstract

Purpose : We investigate the feasibility of Gabor-Domain Optical Coherence Microscopy (GDOCM) for high-resolution three-dimensional corneal imaging and endothelial cell assessment.

Methods : Ten corneas acquired from the Lions Eye Bank at Albany were imaged using GDOCM. The corneas, which are stored in a PMMA viewing chamber after recovery from donors, were imaged through the container. Volumetric images with 1 mm x 1 mm field of view and 2-micron resolution over the entire corneal thickness were collected around the center of each cornea. Due to the curvature of the cornea, the endothelium, a single layer of cells lining the posterior surface of the cornea, cannot be viewed in a single en face image; the 3D images were processed with an custom automated 3D flattening algorithm to present the view of the endothelial cells in a single en face image, which can be compared to the endothelial view obtained with a specular microscope commonly used at eye banks and used to assess cell count density.

Results : High-resolution 2D and 3D images of the cornea over a 1 x 1 mm² field of view were collected, as shown in Fig. 1. After applying an automated 3D flattening procedure, the endothelial cells were visualized in a single en face view, as shown in Fig. 2(b). The corresponding image collected with a specular microscope at the eye bank is shown in Fig. 2(a). Cell count density is assessed from the en face view of the endothelium.

Conclusions : GDOCM was used to image and evaluate ten corneas. GDOCM was shown to image all corneal layers across a large field of view with cellular resolution. A custom 3D flattening algorithm was applied to each cornea to produce an en face view of the endothelium from which the cell count was obtained and compared with the gold standard of specular microscopy.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Figure 1 - Excised human cornea imaged with GDOCM through the viewing chamber over a field of view of 1 mm x 1 mm. (a) Cross-sectional view of the full thickness of the cornea (endothelium side up). (b) En face view of the transition between corneal endothelium and stroma. (c) 3D rendering.

 

Figure 2 - Corneal endothelium imaged by (a) specular microscopy (Konan CellChekD+) over a field of view of 0.75 mm x 1 mm and by (b) GDOCM over a field of view of 1 mm x 1 mm. Bars are 100 mm. The specular microscope imaging was conducted 21.5 hours after death, while GDOCM imaging was conducted 6 days and 21 hours after death