Monitoring Corneal Hydration With a Mid-infrared (IR) Laser

A mid-infrared (IR) source at ∼ 3 μm radiation is used as a probe to measure hydration in porcine cornea. Since the Er3+:YAG emission targets vibrational modes (around 3300cm−1) in the H2O molecule, it is highly sensitive to changes in water content in the first ∼10 μm of the corneal tissue.