Abstract
Abstract: :
Purpose: To evaluate the ability of conventional optical coherence tomography (OCT) and new version of OCT (OCT-3) in visualizing the microstructure of anterior chamber angle. Methods: Microscopic angle analysis using OCT and OCT-3 (Carl Zeiss Co.) was performed on the excised porcine eyes, human volunteers, and human glaucoma patients with or without gonioprism lens (RGO, Rodenstock). Excised porcine eyes were secured in a purpose-built holder, placed in front of the equipment, attached to a gonioprism lens if necessary, and optically sectioned in various directions. Human volunteers and glaucoma patients including primary open angle glaucoma, normal tension glaucoma, and post-trabeculectomy patients, after providing informed consent, were topically anesthetized and measured with the same manner. OCT and OCT-3 images were then compared with the sectional images as seen under light microscope prepared from the frozen slices of porcine eyes, or with the slit lamp gonioscopic findings of human subjects. Results: Compared with the conventional OCT, the spacial resolution of OCT-3 was much higher in both horizontal and vertical direction. Without gonioscopy, strong scattering of the laser light from the limbal sclera prevented the angle structure from being visualized in details in both porcine and human eyes, while with the assistance of gonioscope, clear images of the anterior chamber angle including trabecular beams were easily obtained. Histological and biomicroscopical findings confirm that the OCT-3 images nicely reflected the original structure both in porcine and human eyes. Conclusions: OCT-3 is useful for analyzing the microstructure of the anterior chamber angle non-invasively. Optical coherence goniomicroscope with OCT-3 may lead to further understanding of angle structure, mechanism of angle closure, and outflow facility of aqueous humor after the glaucoma surgery.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • trabecular meshwork