Since its innovation in 1997, PS-OCT was nice to qualitatively visualize the tissue birefringence. However, its quantification ability was low. It was mainly because its non-linear and complex effects of measurement noise into the birefringence values to be measured. To be honest, the raw birefringence value measured by PS-OCT has not been reliable at all.
Our colleagues Deepa Kasaragod recently developed a mathematical framework to accurately estimate the tissue birefringence from the raw birefringence values measured by PS-OCT. She first numerically characterized the relationship between the measurement noise and measured birefringence values. And then, she designed a mathematical frame work, by using a Bayesian rule together with the numerically obtained property, to obtain a “maximum likelihood estimation” of the tissue birefringence.
Both numerical and experimental validations proved that this framework has high ability to quantitate the birefringence. This method was recently published in Optics Express (full citation is shown below). In this paper, some in vivo human eye results including a pathologic case (anterior eye of trabeculectomy bleb) are presented.
Currently, a clinical study with this method is ongoing. I believe we can present impressive clinical results soon. The details of the technology are now available on the following paper.
Full length article (open access)
D. Kasaragod, S. Makita, S. Fukuda, S. Beheregaray, T. Oshika, and Y. Yasuno, Optics Express 22, 16472-16492 (2014), http://dx.doi.org/10.1364/OE.22.016472
Joschi, Yoshiaki Yasuno