Abstract
Purpose: :
To observe changes of human donor cornea in response to intraocular pressures (IOP) variation by full-field optical coherence tomography (OCT).
Methods: :
The human donor cornea for experimental use was mounted on a Barron artificial anterior chamber, and the hydrostatic pressure by the BSS Plus solution (37 degrees) was altered from 18 mmHg to 50 mmHg. A full-field OCT system capable of capturing a horizontal cross-sectional image in real time was employed, providing a field of view of 420 µm ×420 µm, with a lateral resolution of 2.6 µm ×2.6 µm. The longitudinal resolution was 5 µm. Full-field OCT images were taken from the epithelial side to the endothelial side at a 5 µm step interval. Morphological change of the corneal cells, increase of image intensity, and thickened of the corneal length were observed.
Results: :
Contrast of the cell boundaries increased with the IOP at the wing cell layer and the basal cell layer of the epithelium, and also the keratocyte. With an average increase of 27% in the total corneal thickness observed at the present IOP range, the increase in the epithelium thickness (28 µm, 34%) appeared to be more obvious than that in the stromal (140 µm, 28%). Meanwhile, the mean image intensity at the wing cell layer, basal cell layer, superficial stroma (100 µm depth), and mid-stroma (200 µm) increased by a factor of ×3.0, ×1.5, ×1.4, and ×1.1, respectively.
Conclusions: :
In addition to the qualitative changes in morphological structures, the epithelial and stromal thicknesses and the image intensity at each level of human donor cornea during IOP change can be measured quantitatively by full-field OCT.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • anterior segment • intraocular pressure