Imaging the anterior eye segment by polarization-sensitive spectral- domain and swept-source optical coherence tomography

摘要

Polarization-sensitive optical coherence tomography (PS-OCT) has been developed to measure the birefringent properties of the human eye. In the retina, retinal nerve fiber layer and retinal pigment epitherial layer have the characteristic birefringent properties. In addition to such normal tissue, abnormal fibrous tissue of the retina can be detected by PS-OCT. In the anterior segment, the cornea is a birefringent tissue due to the multi-layered fibril structure. The sclera and tendon also have the birefringence and the contrast of these structures can be enhanced by PS-OCT. These studies have been used time-domain or spectral-domain PS-OCT. Recently, swept-source OCT (SS-OCT) has been applied for anterior eye segment imaging. At the 1.3 um wavelength, SS-OCT is more promising than spectral-domain OCT, because the available camera for the spectrometer is limited. Three-dimensional imaging of the anterior segment is possible owing to the high penetration, high acquisition speed and high sensitivity. We have developed a new system of SS-OCT with polarization sensitivity. In this study, we measure the birefringent properties of anterior eye segment by polarization-sensitive spectral-domain OCT (PS-SD-OCT) at 840 nm and polarization-sensitive swept-source OCT (PS-SS-OCT) at 1.3 um, and evaluated the possibilities for clinical application.