Abstract
Purpose :
To visualize and quantify the thickness profiles of varying corneal layers of the non-human primates using ultra-high resolution optical coherence tomography (UHR-OCT).
Methods :
A total of 19 eyes from 10 healthy non-human primates were imaged, in particular both eyes of nine Macaca fascicularis monkeys (n = 18 eyes) and one eye of a common Marmoset (n = 1 eye). A custom-built spectral domain UHR-OCT system in tissue was used to acquire in vivo UHR-OCT tomograms of the cornea. Briefly, the system operates in 800nm region with a spectral bandwidth of 165nm, providing a 1.2µm axial resolution and 8µm lateral resolution in tissue. The interferometric signal was dispersed by a customized high-resolution spectrometer and collected by a line-scan CMOS camera operating at 140kHz (Basler). Cross sectional images were taken ~1mm inferior to the cornea apex to avoid strong reflection. A custom MATLAB algorithm was used to extract the images from spectral data, where the images were later exported to ImageJ (NIH, USA) for thickness measurement. Three measurements were conducted and averaged from each cross-sectional image.
Results :
Three distinct corneal layers were visualized where the average thicknesses of the corneal epithelium, stroma and endothelium of the Macaca fascicularis eyes were 55.1 ± 7.2 µm, 598.3 ± 52.5 µm and 8.7 ± 1.1 µm, respectively. In the marmoset, the average thickness of the corneal epithelium, stroma and endothelium was 45.3 ± 1.1 µm, 444.8 ± 20.2 µm and 6.7 ± 0.4 µm, respectively.
Conclusions :
In this study, we describe the successful delineation of corneal layers in non-human primates with an ultrahigh resolution OCT system. This may contribute to future studies to use UHR-OCT for anterior segment imaging to investigate the morphology and translational work.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.