Abstract
Abstract: :
Purpose: The goal of this study is to develop a retinal tomograph which combines the transversal imaging mode of a confocal scanning laser tomograph with the depth resolution of optical coherence tomography (OCT). Methods: A three-dimensional OCT setup was developed by integrating a low coherence interferometer into a confocal scanning laser system TopSS (Laser Diagnostic Technologies, Inc.) with a superluminescent diode as the light source. Where conventional OCT generates a cross-section of the retina by performing adjacent A-scans, our 3-D OCT acquires section images parallel to the retinal surface at defined depths across the thickness of the retina. Image acquisition time was 32 transversal OCT images in 1 second. The operator could select the image field size and scan depth range. In vivo measurements were performed in healthy volunteers at a field size of 10º by 10º or larger. Results: Three-dimensional distribution of light-remitting sites within the retina were recorded with a depth resolution of approximately 16 microns. In vivo measurements were relatively easy to perform. Transversal section images at various depths of the retina were displayed, as well as cross-sections of the retina from any location within the 10º by 10º area. Different retinal structures: internal limiting membrane, RPE, nerve fiber layer, fovea, and nerve head were clearly observed. Conclusion: 3-D OCT is a rapid and easy method to obtain high resolution 3-D retinal images. This is a significant improvement over conventional OCT where only one cross-section can be recorded per measurement and the location and section geometry has to be defined prior to data acquisition.
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 554 retina • 484 nerve fiber layer