In Vivo Human Corneal Confocal Microscopy of Identical Fields of Subepithelial Nerve Plexus, Basal Epithelial, and Wing Cells at Different Times

A technique is described to obtain time-lapse reflected light confocal images of cells in the basal epithelium and adjacent wing cell layer from the in vivo human cornea. The technique is based on the sequential relocation of the unique patterns of the subepithelial nerve plexuses immediately posterior to Bowman's membrane. The patterns of individual subepithelial nerve plexuses, as well as perforation points where nerves traverse Bowman's membrane, serve as fixed landmarks. A real-time, scanning slit, confocal microscope is used to obtain reflected light images of a subepithelial nerve plexus, and the anterior and adjacent fields of basal and wing cells in the in vivo human cornea. All of the photographs are obtained from single video frames without the necessity of frame averaging or digital image processing. The instrument and relocation technique are prerequisites for applying a time-lapse observation technique to investigate the dynamics of basal cell proliferation and differentiation in the living eye.