Method for Assessing Local Mechanical Properties of the Cornea Based on Spectroscopic Magnetomotive Optical Coherence Elastography.

OBJECTIVE

Current methods for assessing corneal mechanical properties are limited, particularly in their ability to provide localized information. This study proposes a novel approach based on the spectroscopic magnetomotive optical coherence elastography (MM-OCE) technique, aiming to enable non-invasive, localized evaluation of corneal mechanical properties.

METHODS

Magnetic nanoparticles (MNPs) were distributed on sample surfaces to induce vibrations via magnetic excitation. A spectral-domain OCT system combined with phase-sensitive OCT analysis tracked mechanical responses. Gelatin phantoms (varying stiffness) and ex vivo porcine corneas (untreated vs. crosslinked [CXL] regions) were tested. MB-mode validated MNP-induced vibrations, while M-mode scans and spectral analysis determined resonance frequencies. Histology assessed tissue integrity post-MNP application.

RESULTS

Gelatin resonance frequencies increased with concentration, confirming sensitivity to mechanical variations. In corneas, MM-OCE detected significant differences between untreated and CXL-treated regions: resonance frequencies rose from 74.48 ± 6.23 Hz (untreated) to 83.42 ± 4.97 Hz (1-min UV), 110.92 ± 2.40 Hz (3-min UV), and 121.23 ± 3.02 Hz (6-min UV). Histology confirmed no MNP-induced tissue damage.

CONCLUSION

MM-OCE effectively differentiates localized biomechanical changes in corneal tissue, demonstrating feasibility for quantifying stiffness variations induced by CXL.

SIGNIFICANCE: Although further improvements are needed for potential clinical applications, this study demonstrated that MM-OCE may offer a promising, non-invasive method for assessing local mechanical properties of a cornea, with the potential to enhance early diagnosis, treatment planning, and monitoring in ophthalmology.