Ex vivo and in vivo OCT image contrast

We present results of OCT and polarization-OCT applied to various ex vivo tissue samples and discuss related issues of image contrast, comparing in vivo and ex vivo preparations. Time-domain and frequency-domain OCT at 835nm and 1300nm have been applied to ex vivo skin and rabbit cornea. We can distinguish rabbit cornea epithelium for up to a month after excision. However, the skin loses all contrast upon excision and despite numerous experiments we cannot distinguish epidermis, which is clearly visible in vivo. Using a time-domain system, birefringence is clearly visible for decalcified tissue but can also be detected more weakly on fully mineralised tissue. Analysis suggests that demineralization increases the birefringence value.