<title>Application of phase stepping imaging polarimetry technique in ophthalmology</title>

Abstract

The cornea is the outermost segment of the eyeball. Due to it's lamellar structure the cornea indicates the optical anisotropy and effect of birefringence. We have applied phase stepping imaging polarimetry to measure birefringence of the human cornea in vivo and in vitro. Investigation of the corneal birefringence could be useful for eamining the inner corneal structure, its lamellar arrangement and in medical diagnosing of cornea! pathologies. There are also some potential applications of this method in transplantation of human corneas and refractive surgery procedures. The phase stepping imaging polarimetry technique used here, allows calculating azimuth angle, phase retardation and transmission coefficient of the sample. The method uses simple setup, sample at rest, and enables fast and accurate acquisition of data. The theory ofthe method is included. Experimental results of azimuth angle and phase retardation distribution for human cornea in vivo and in vitro are also presented.

The theory and implications of the biaxial model of corneal birefringence

“…, 2005). The assumption that optical birefringence can provide information on ocular biomechanics has been central to the development of different polarimetric methods for examining corneas both in vitro (Jaronski and Kasprzak, 1999) and in vivo (Jankowska‐Kuchta et al. , 1996; Bueno et al.…”

“…The postulate that structural anisotropy determines mechanical anisotropy is fundamental to computational models of corneal biomechanics (Pinsky et al, 2005). The assumption that optical birefringence can provide information on ocular biomechanics has been central to the development of different polarimetric methods for examining corneas both in vitro (Jaronski and Kasprzak, 1999) and in vivo (Jankowska-Kuchta et al, 1996;Bueno et al, 2003). Thus, whatever the underlying cause/s of the observed optical anisotropy, the resultant spheroconic distributions of refractive index/vibration direction are a manifestation of a structural geometry that influences corneal biomechanics.…”