We report on a pathway for Gabor domain optical coherence microscopy (GD-OCM)-based metrology to assess the donor’s corneal endothelial layers ex vivo. Six corneas from the Lions Eye Bank at Albany and Rochester were imaged with GD-OCM. The raw 3-D images of the curved corneas were flattened using custom software to enhance the 2-D visualization of endothelial cells (ECs); then the ECs within a circle of 500-μm-diameter were analyzed using a custom corner method and a cell counting plugin in ImageJ. The EC number, EC area, endothelial cell density (ECD), and polymegethism (CV) were quantified in five different locations for each cornea. The robustness of the method (defined as the repeatability of measurement together with interoperator variability) was evaluated by independently repeating the entire ECD measurement procedure six times by three different examiners. The results from the six corneas show that the current modality reproduces the ECDs with a standard deviation of 2.3% of the mean ECD in every location, whereas the mean ECD across five locations varies by 5.1%. The resolution and imaging area provided through the use of GD-OCM may help to ultimately better assess the quality of donor corneas in transplantation.
A Gabor-domain optical coherence microscope (GDOCM) with 2-micrometer invariant lateral and axial resolutions and a working distance of 15 mm was developed for 3D imaging of corneal tissue over a 1 mm2 field of view. The increased working distance over the previous in-contact implementation enables imaging of corneal tissue inside the viewing chamber in which corneas are stored after recovery from donors. The GDOCM system was used to image excised human corneas. 3D images of the cornea were acquired by imaging through the PMMA viewing chamber. The images achieved cellular resolution in the volume being imaged. 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. A flattening algorithm was implemented to obtain an en face view of the endothelium. The GDOCM images were compared with those acquired with a specular microscope commonly used in eye banks for endothelial evaluation, and the endothelial cell density was assessed for both sets of images. A key advantage of GDOCM is the capability to image the entire thickness of the cornea in 3D with cellular resolution over a large field of view.