Corneal Epithelial Thickness Profile in the Diagnosis of Keratoconus

An epithelial doughnut pattern appears to indicate the presence of an underlying stromal cone; the lack of an epithelial doughnut pattern would indicate that an abnormal topography was not due to keratoconus. In very early keratoconus, epithelial compensation can mask the presence of an underlying cone on front surface topography, ie, a diagnosis of keratoconus might be missed.