Dual Optical Elastography Techniques Reveal the Regulation of Corneal Stiffness by Collagen XIV

Abstract

Collagen XIV is a fibril-associated collagen with interrupted triple helices (FACIT) that helps regulate collagen fibril spacing, alignment, and extracellular matrix organization. Its role in corneal biomechanics remains incompletely understood. Here, we investigated murine wild-type (WT) and collagen XIV-deficient (Col14a1^−/−) corneas using complementary optical elastography modalities: Brillouin microscopy and air-coupled ultrasound optical coherence elastography (ACUS-OCE). Brillouin microscopy generated high-resolution maps of Brillouin frequency shift in WT and Col14a1^−/− corneas (N = 4 per group), while ACUS-OCE measured elastic wave speed in WT (N = 8) and Col14a1^−/− (N = 7) corneas. Both methods showed reduced mechanical metrics in Col14a1^−/− corneas, with lower Brillouin frequency shift and lower OCE-derived wave speed relative to WT controls. These findings support collagen XIV as a regulator of corneal stromal biomechanics and demonstrate the value of combining Brillouin microscopy with ACUS-OCE for detecting biomechanical alterations in murine corneas.