Subsurface imaging of living skin with optical coherence microscopy

A new type of microscope has been developed for acquiring cross-sectional images of living skin noninvasively. It takes advantage of the short temporal coherence of a broad-band light source to reject scattered light. Because this microscope is still in an early stage of development, its potential as a diagnostic tool in dermatology has not yet been determined.

This study was designed to explore potential applications of optical coherence microscopy in dermatology. The aim was to investigate the structures in skin that can be seen without staining or using sophisticated image-processing methods.

A prototype fiberoptic microscope was assembled that uses a 1,300-nm light-emitting diode as a light source. Scans were obtained from the skin on the index finger and forearm. Subsurface structures were identified based on knowledge of the anatomy of normal healthy skin.

Structures located as deep as 1 mm below the surface of the skin could be imaged with a resolution of about 10 microns in the axial and lateral dimensions. In optical slices taken perpendicular to the skin surface, the contours of the epidermal ridges and the boundary between the epidermis and dermis were readily observed.

The results of this study suggest that an optical coherence microscope may have value as a diagnostic tool for cases in which visualization of subcellular details is not required. The resolution, contrast and scanning speed of the microscope need to be improved.