Utility of regional epithelial thickness measurements in corneal evaluations.

The measurement of regional corneal epithelial thickness and characterization of its behavior in response to changes in corneal architecture are increasingly drawing interest in clinical practice. The epithelium has tremendous capacity for remodeling and does so in response to underlying stromal pathology or changes in anterior corneal curvature. Various remodeling patterns have been identified that help distinguish between ectatic and nonectatic corneal conditions. Epithelial mapping has also facilitated more precise, individualized corneal surface disorder treatments. We highlight the different imaging modalities for epithelium measurement, epithelial remodeling patterns in ectatic disorders and after corneal refractive surgery, discuss utility of epithelial measurement in therapeutic refractive surgery planning, and discuss controversies that exist regarding epithelial remodeling, including its mechanisms and its relative importance in surgical planning and screening evaluations.