Brillouin optical microscopy for corneal biomechanics

Area of Science:

• Ophthalmology
• Biomedical Optics
• Materials Science

Background:

• Corneal mechanical properties are crucial for ocular health and disease.
• Brillouin microscopy offers novel 3D mechanical imaging capabilities.
• Assessing in situ corneal biomechanics is vital for diagnostics and treatment.

Purpose of the Study:

• To evaluate the feasibility of Brillouin microscopy for in situ quantitative assessment of corneal biomechanical properties.
• To demonstrate the technique's ability to image mechanical variations within the cornea.
• To compare Brillouin measurements with conventional mechanical testing.

Main Methods:

• Utilized Brillouin light-scattering with a 532-nm laser and high-resolution spectrometer.
• Performed confocal scanning for Brillouin elasticity imaging of bovine corneas.
• Measured longitudinal elastic modulus before and after riboflavin cross-linking, comparing with stress-strain tests.

Main Results:

• Obtained high-resolution Brillouin images revealing depth-dependent elastic modulus variations.
• Observed gradual changes in Brillouin frequency shift from epithelium to endothelium (8.2 GHz to 7.5 GHz).
• Demonstrated significant alterations in axial Brillouin profiles post-riboflavin cross-linking (P < 0.001).

Conclusions:

• Brillouin imaging provides high-resolution, in situ assessment of corneal biomechanics.
• The technique shows potential for clinical diagnostics and monitoring of ophthalmic treatments.
• Corneal cross-linking significantly alters mechanical properties measurable by Brillouin microscopy.