Corneal hydration assessment indicator based on terahertz time domain spectroscopy

Area of Science:

• Ophthalmology
• Biomedical Optics
• Terahertz Spectroscopy

Background:

• Corneal water content is crucial for ocular health.
• Accurate measurement of corneal hydration is essential for diagnosing and managing eye conditions.
• Existing methods for measuring corneal water content have limitations.

Purpose of the Study:

• To introduce a novel indicator, the characteristic ratio (CR), for characterizing corneal hydration using terahertz time-domain spectroscopy.
• To establish the relationship between CR and corneal water content.
• To evaluate the potential of this method for in-vivo applications.

Main Methods:

• Terahertz time-domain spectroscopy was employed to collect reflection spectra from ex vivo human corneal stroma samples.
• Samples underwent dehydration under controlled natural conditions (22.4°C, 20% humidity).
• A characteristic ratio (CR) was calculated from the sum of low (0.2-0.7 THz) and high (0.7-1.0 THz) frequency spectral intensities after error elimination.

Main Results:

• The study established corresponding relationships between the calculated CR and the actual corneal water content.
• The developed CR method demonstrated improved accuracy compared to previous studies, with lower coefficients of variation for fitting slope (39.4%) and intercept (27.6%).

Conclusions:

• The characteristic ratio (CR) derived from terahertz time-domain spectroscopy is a viable indicator for assessing corneal hydration.
• This terahertz-based approach shows significant potential for accurate and non-invasive in-vivo corneal water content measurement.
• Further research could lead to clinical applications for diagnosing and monitoring ocular health.