Abstract
Abstract: :
Purpose: To distinguish different ocular tissues on the basis of its response to illumination with polarized light. To establish a normal pattern of the polarization properties of ocular tissue. Methods: A phase resolved polarization sensitive optical coherence tomography (PS–OCT) system based on a transversal scanning of the eye was developed and used to image different ocular tissues. The instrument measures backscattered intensity, retardation and fast axis orientation, simultaneously. A depth resolution down to few micrometers could be achieved in the anterior segment. Cornea, iris, lens and retina of healthy human volunteers were measured with our system. Results: The corneal epithelium, Bowman’s layer, endothelium, upper layers of the iris, lens and several layers of the retina were found to preserve the polarization state of the incident light. The light backscattered from the pigment epithelium of the iris and from near the retinal pigment epithelium was found to be depolarized. A fraction of the light backscattered from within the corneal stroma was also found to be depolarized. Conclusions: PS–OCT represents a powerful tool to increase image contrast in ocular tissues. The observed polarization preserving and depolarizing tissue structures can be used as a standard for comparison with pathologic changes. The light backscattered from within the corneal stroma originates from two different kinds of particles (polarization preserving and depolarizing).
Keywords: anterior chamber • retina • cornea: basic science