Abstract: The invention provides a method for using OCT human tissue scan data for tracking a scan structure in depth, follow change in structure position within an OCT scan from, for example, fasting glucose level to peak glucose level and back down again, and relate the structure position change to analyte concentration. In the preferred embodiment, the analyte of interest is glucose concentration and the target of interest is living human skin. A hyaluronic acid based mechanism is suggested for dermis thickness. Alternate embodiments of the method are presented, including curve fitting of topographic regions corresponding to trackable target features.