Abstract
Purpose: :
The low coherence nature of the source in both time and space in the full–field optical coherence tomography (OCT) system has advantages over the conventional OCT system, making it one of the attractive methods for the non–invasive imaging of the cornea at subbiomicroscopic levels. In the study, the feasibility of our full–field OCT system was investigated for the ultra–high resolution imaging of the cornea.
Methods: :
Corneas in excised porcine eyes and those in human eye bank eyes were used for the study. These samples were illuminated with the probe beam and a horizontal cross–sectional image is detected using a CCD camera. To extract the interference component from the output of the CCD camera, a phase–shift detection technique was employed. Structures of the epithelium, stroma, and endothelium of porcine corneas and human cornea were observed with a field of view of 850 µm x 850 µm and a 2.6 µm x 1.7 µm (longitudinal x transverse) resolution.
Results: :
Starting from the epithelial side to the endothelial side a series of horizontal cross–sectional still images were obtained at a 2–µm step. In the porcine cornea and human cornea, superficial cells, wing cells, basal cells, nerve plexus, stromal keratocytes, and endothelium were clearly revealed. In addition, filaments throughout the stroma and the Descemet's membranes with the anterior and posterior bands were well recognized. Full–field OCT imaging provided the detail of corneal structures comparable to those of in vivo confocal microscopy.
Conclusions: :
The ultrahigh resolution of full–field OCT may become a powerful tool for visualizing the morphological structure of cornea layer by layer with repeated and non–invasive fashion.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • imaging/image analysis: non-clinical • cornea: basic science