Epithelial Mapping in Corneal Ectasias: A Narrative Review

Abstract

Corneal ectasias, including keratoconus, pellucid marginal degeneration, and post-refractive surgery ectasia, are progressive disorders that can significantly impair vision if not detected early. In recent years, epithelial thickness mapping (ETM) has emerged as a valuable adjunct to conventional corneal imaging. This review explores the biological basis, technological advances, and clinical applications of ETM in the diagnosis and management of ectatic corneal diseases. The corneal epithelium demonstrates dynamic remodeling in response to underlying stromal changes, often masking early pathology on standard topography. ETM leverages this compensatory behavior to reveal subtle abnormalities, enabling earlier detection of subclinical disease.