Method and system for removing the effects of corneal birefringence from a polarimetric image of the retina

摘要

A scanning laser polarimetry (SLP) system that measures retinal nerve fiber layer (RNFL) retardance in a single scan image with improved sensitivity. An external bias retarder in combination with the anterior segment retardance forms a nonzero joint retardance adapted to enhance the signal-to-noise ratio (SNR) of the SLP system. With such a simple bias retarder, the effects of anterior segment retardance (delta_C, theta_C) may be removed from a single polarimetric image of the retina without a direct cancellation by a variable corneal compensator (VCC) by the method of this invention. Using a single polarimetric image is particularly advantageous for simplicity and accurate corneal compensation. The simple bias retarder may be embodied as a VCC or any useful external retarder, for example.