Confocal reflectance theta line scanning microscope for imaging human skin in vivo.

A confocal reflectance theta line scanning microscope demonstrates imaging of nuclear and cellular detail in human epidermis in vivo. Experimentally measured line-spread functions determine the instrumental optical section thickness to be 1.7 +/- 0.1 microm and the lateral resolution to be 1.0 +/- 0.1 microm. Within human dermis (through full-thickness epidermis), the measured section thickness is 9.2 +/- 1.7 microm and the lateral resolution is 1.7 +/- 0.1 microm. An illumination line is scanned directly in the pupil of the objective lens, and the backscattered descanned light is detected with a linear array, such that the theta line scanner consists of only seven optical components.