Long-Term Corneal Reshaping Using Riboflavin-UVA Crosslinking Combined With Decorin in Rabbits

To establish a preclinical proof of concept for a novel, non-ablative method for long-term corneal reshaping and to investigate its biomechanical and safety profiles.

A rabbit model of non-ablative corneal reshaping was established using a custom molding device. The optimal protocol involved stromal reshaping stabilized by riboflavin-ultraviolet A (UVA) collagen cross-linking (CXL; 7.2 J/cm2), with topical decorin applied as a biological modulator to maintain corneal clarity. Corneal topography was monitored for 12 months. Safety was assessed via in vivo clinical examinations, histology, and electron microscopy. Biomechanical properties were evaluated ex vivo via uniaxial tensile testing of rabbit corneas and human corneal lenticules.

In vivo, extensive reshaping with fixation induced significant corneal flattening (6.55 ± 1.44 D at 1 month, stabilizing to 6.19 ± 1.12 D at 12 months; P < 0.05 vs. controls). Mild reshaping yielded 3.13 ± 1.07 D flattening (1 month), but reshaping alone showed no significant effect (P > 0.05). One-month safety evaluations were favorable, demonstrating normal corneal architecture and no cytotoxicity. Ex vivo biomechanics were significantly enhanced by the combined CXL-decorin treatment compared to CXL alone.

Combining mechanical molding with a CXL-decorin fixation protocol can achieve durable, non-ablative corneal reshaping, with the observed 12-month stability underpinned by enhanced biomechanical stiffness. This approach is a promising strategy for refractive correction and may have future applications in corneal ectatic diseases.

This preclinical study validates the long-term safety and efficacy of a non-ablative, stromal-preserving, corneal-reshaping protocol, supporting its potential clinical translation for myopia.