Abstract
Purpose :
To investigate the feasibility of using the Terahertz (THz) scanning system as a quantitative tool to evaluate corneal edema, and to evaluate the correlation between the signal intensity generated by the THz scanning and the central corneal thickness (CCT) measured by anterior segment optical coherence tomography (ASOCT).
Methods :
Twenty human cadaveric corneas with different extents of corneal edema resulting from different preservation time were used. All the corneas were scanned weekly for longitudinal 3 weeks, with the TPS Spectra 3000 Teraview Terahertz scanning system and ASOCT (RTVue). The area under the curve (AUC) of the THz peak intensity from the spectral domain was calculated, and was correlated with the CCT measurements.
Results :
At baseline (upon arrival), the THz scanning system had the capability to differentiate different extents of corneal edema resulting from different preservation time (Figure 1). The signal intensity increased with time as the cornea became more edematous (Figure 2). In the weekly continuous scans of these 20 corneas, a total of 400 THz scanning was obtained, and the AUC of signal intensity ranged from 6830±1289 to 13544±2593 atomic units/THz. The CCT ranged from 585±24to 1272±48μm. The AUC was positively and strongly correlated with the CCT (r = 0.77, P = 0.011) when the CCT < 800 μm. The correlation was slightly lower when the CCT > 800 μm but was still significant (r= 0.56; P= 0.014).
Conclusions :
The Terahertz scanning has the potential to be used as a novel tool to quantitatively evaluate corneal edema. It may be helpful in monitoring the disease progression in patients with corneal edema.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.