Excimer laser-assisted corneal epithelial pattern ablation for corneal cross-linking

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Corneal Science

Background:

• Corneal cross-linking (CXL) is a treatment to strengthen the cornea.
• Standard CXL involves epithelial removal, which can be invasive.
• Excimer laser-assisted patterned de-epithelialization offers a potentially less invasive alternative.

Purpose of the Study:

• To evaluate the efficacy of corneal cross-linking (CXL) using excimer laser-assisted patterned de-epithelialization.
• To assess chromophore penetration into the corneal stroma following this de-epithelialization method.

Main Methods:

• Porcine eyes underwent either full mechanical or patterned excimer laser de-epithelialization.
• Corneas were impregnated with riboflavin (RF) or water-soluble taurine (WST11).
• Corneal stiffening was measured by strip extensiometry; chromophore penetration was assessed via spectrophotometry and fluorescence microscopy.

Main Results:

• All tested chromophores induced significant CXL, with comparable stiffening across formulations and de-epithelialization methods.
• Patterned de-epithelialization resulted in significantly higher light transmittance compared to full de-epithelialization.
• Stromal chromophore penetration was comparable between full and patterned de-epithelialized samples.

Conclusions:

• Excimer laser-assisted patterned de-epithelialization is effective for CXL.
• Reduced stromal chromophore concentration may raise safety concerns for UVA-based CXL.
• Further in vivo studies are required to validate the safety and benefits of this technique for corneal CXL.