Key Takeaways

  • A new study shows corneal endothelial cell density declined significantly with increasing keratoconus severity and patient age

  • Mean baseline ECD was 2,802 ± 285 cells/mm² across 477 eyes, with only one eye below 2,000 cells/mm²

Epion Therapeutics announced the publication of a peer-reviewed study in Cornea demonstrating that corneal endothelial cell density (ECD) declines significantly with increasing keratoconus severity and age but remains within the physiological range in nearly all affected eyes.1

The study, conducted in collaboration with the Corneal Image Analysis Reading Center (CIARC) at the UH Eye Institute in Cleveland, analyzed baseline data from 254 patients (477 eyes) enrolled across 11 clinical sites in Epion's phase 3 program evaluating EpiSmart epithelium-on corneal cross-linking for keratoconus.

Using specular microscopy and corneal tomography, investigators examined associations between central ECD and several indicators of keratoconus severity, including corneal curvature, thickness, and elevation.

Results showed a statistically significant reduction in ECD with increasing disease severity and age. However, endothelial cell counts remained within physiological limits in nearly all eyes, including those with advanced keratoconus. Mean baseline ECD was 2,802 ± 285 cells/mm², and only one eye had an ECD below 2,000 cells/mm².

The analysis represents the first peer-reviewed publication from Epion's phase 3 clinical program. Although the data were collected during trials evaluating EpiSmart, the reported findings concern baseline endothelial characteristics rather than treatment efficacy or safety outcomes.

Reference

1. Belin MW, DeMarchi J, Benetz BA, et al. A multicenter, randomized, double-masked, sham-controlled phase 3 study to evaluate the efficacy and safety of epithelium-on corneal crosslinking in keratoconus subjects 8 to 45 years of age: baseline endothelial studies. Cornea. Published online April 8, 2026. doi:10.1097/ICO.0000000000004160