Oral Riboflavin for Sunlight-Induced Corneal Cross-linking: Efficacy Assessment in a Rabbit Model In Vivo Using...

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Corneal Science

Background:

• Keratoconus is a progressive eye condition causing thinning and bulging of the cornea.
• Standard corneal cross-linking (CXL) stiffens the cornea to halt progression but is invasive.
• Exploring non-invasive, cost-effective alternatives for keratoconus treatment is crucial.

Purpose of the Study:

• To evaluate the efficacy of a non-invasive approach using oral riboflavin and natural sunlight for keratoconus treatment.
• To determine if this method offers a cost-effective alternative to standard CXL.

Main Methods:

• A prospective, controlled study in New Zealand White rabbits.
• Quantified stromal riboflavin levels after oral administration.
• Assessed corneal biomechanics using optical coherence tomography (OCT) elastography and uniaxial stress-strain extensometry after sunlight exposure.

Main Results:

• Oral riboflavin administration resulted in low stromal riboflavin concentrations, significantly lower than standard CXL.
• No significant corneal stiffening was observed in rabbits treated with oral riboflavin and sunlight compared to controls.
• OCT elastography indicated increased posterior corneal strain in treated eyes, suggesting reduced apparent stiffness.

Conclusions:

• Oral riboflavin combined with natural sunlight did not induce corneal stiffening in the tested rabbit model.
• The low stromal riboflavin levels suggest this approach is unlikely to be an effective standalone keratoconus treatment.
• Observed changes may indicate stromal degradation or subthreshold effects rather than true cross-linking.