Assessing UVA and Laser-Induced Crosslinking via Brillouin Microscopy

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Materials Science

Background:

• Corneal ectatic disorders degrade collagen, impairing biomechanical integrity.
• Ultraviolet-A (UVA) crosslinking is the standard treatment but has limitations in depth and precision.
• Unwanted side effects can occur due to imprecise UVA crosslinking.

Purpose of the Study:

• To compare the biomechanical changes induced by UVA and near-infrared femtosecond laser corneal crosslinking.
• To evaluate the precision and effectiveness of femtosecond laser crosslinking for corneal ectatic disorders.

Main Methods:

• Brillouin microscopy was used to map 3D biomechanical properties (Brillouin frequency shift).
• Corneal samples were crosslinked using both UVA irradiation and a near-infrared femtosecond laser.
• Changes in biomechanical properties were quantified in the crosslinked regions.

Main Results:

• UVA crosslinking resulted in an average Brillouin frequency shift increase of approximately 100 MHz.
• Femtosecond laser crosslinking demonstrated targeted spatial and axial precision.
• The biomechanical changes (Brillouin frequency shift) from femtosecond laser crosslinking were comparable to UVA crosslinking.

Conclusions:

• Near-infrared femtosecond laser crosslinking provides a precise alternative to UVA treatment for corneal ectatic disorders.
• This laser-based method achieves similar biomechanical enhancement to UVA crosslinking with improved spatial control.
• Femtosecond laser crosslinking shows potential for safer and more effective treatment of conditions like keratoconus.