2 research outputs found
Extended in vivo anterior eye-segment imaging with full-range complex spectral domain optical coherence tomography
Polarimetric analysis of the human cornea measured by polarization-sensitive optical coherence tomography
Corneal polarimetry measurement has been the object of
several papers. The results of techniques like polarization-sensitive
optical coherence tomography PS-OCT , scanning laser polarimetry,
or polarization microscopy are contradictory. Some studies propose a
biaxial-like birefringence pattern, while others postulate that birefringence
grows at corneal periphery. Several theoretical approaches
were proposed for the interpretation of these measurements, but they
usually lack accuracy and an adequate consideration of the nonnormal
incidence on the tissue. We analyze corneal polarization effects
measured by PS-OCT. In vivo and in vitro PS-OCT images of the
human cornea are acquired. PS-OCT measurements are apparently
not in agreement with the biaxial-like birefringence pattern. We
present a polarimetric model of the human cornea based on the extended
Jones matrix formalism applied to multilayered systems. We
also apply the PoincarƩ equivalence theorem to extract optic axis
orientation and birefringence. The results show that for a fibrils orientation
pattern composed by alternating circular and radial fibrils, the
birefringence is biaxial-like at the corneal center, and there is an almost
circularly symmetric high-birefringence area at corneal periphery.
The model could be useful for diagnosis of corneal diseases or
corneal compensation in retinal polarimetric imaging