Colour wide field specular microscopic investigation of corneal surface disorders.

Colour wide field specular microscopy (WFSM) may be used to examine different phases of corneal surface pathology in vivo. A soft contact lens facilitates colour differentiation of cell surface variations by interference. Pathologic states may be characterised by modifications in apparent cell colour, brightness, morphology and configuration. Cell brightness is altered by interference phenomena, cell surface irregularities (microprojections), homogeneity of substances covering cells, intracellular components and changes in indices of refraction at the interfaces between the cell surface and the tear layers. Colour photography has been helpful in deciding which intensity variations may be due to interference effects.