This is part of the OCT or optical coherence tomography channel or lecture series.  This is an overview of adjuvant techniques beyond pure structural OCT.  These techniques, which extend the capabilities of OCT, are powerful.  They include PS-OCT, OCT elastography, and photon tagging.  However, around 2010 they somewhat came to a halt.  The stagnation period of OCT, between 2000-2015, when morbidity and mortality data was not generated, funding was reduced waiting for groups to arise that did double blind clinical trials.