Differentiating pellucid marginal degeneration from keratoconus with epithelial mapping

Introduction: Keratoconus and pellucid marginal degeneration are corneal ectatic disorders which cause thinning of cornea. They can be differentiated by epithelial mapping as keratoconus shows a typical appearance. Objective: To differentiate pellucid marginal degeneration from keratoconus with epithelial mapping. Methodology: It is a case series observational study of four young adults carried out over period of one month from September 2021 to October 2021. Conclusion: Even though in some cases of keratoconus and pellucid marginal degeneration show similar topography pattern, keratoconus shows typical "doughnut" appearance in epithelial mapping and PMD shows inferior thinning of epithelium in epithelial mapping.