Static compression optical coherence elastography for the measurement of porcine corneal mechanical properties ex-vivo

Significance

The biomechanical properties of the cornea are important for vision and ocular health. Optical coherence elastography (OCE) has the potential to improve our capacity to measure these properties.

Aim

This study tested a static compression OCE method utilising a commercially available optical coherence tomography (OCT) device, to estimate the Young’s modulus of ex-vivo porcine corneal tissue.

Approach: OCT was used to image corneal tissue samples before and during loading by static compression. The compressive force was measured with a piezoresistive force sensor, and tissue deformation was quantified through automated image analysis. Ten ex-vivo porcine corneas were assessed and the corneal thickness was also measured to assess the impact of corneal swelling.

Results

An average (standard deviation) Young’s modulus of 0.271 (+/- 0.091) MPa was determined across the 10 corneas assessed. There was a mean decrease of 1.78 % in corneal thickness at the end of the compression series. These results showed that there was a moderate association between corneal thickness and the Young’s modulus recording (R² = 0.274).

Conclusions

Optical coherence elastography utilising clinical instrumentation, can reliably characterise the mechanical properties of the cornea. These results support the further investigation of the technique for in-vivo measurement of the mechanical properties of the human cornea.