Assessment of the Safety of THz Irradiation on the Morphofunctional Characteristics of Rabbit Corneas

The morphofunctional characteristics of rabbit corneas were studied after terahertz (THz) irradiation at a frequency of 2.3 THz with varying durations (15 or 30 min) or intensities (0.012 mW/cm² (38°C), 0.018 mW/cm² (40°C), 0.024 mW/cm² (42°C)) over a period of 1 week after exposure. The intensity of irradiation did not affect the functional changes in the eyes after exposure. However, in groups with different exposure durations, statistically significant changes in corneal hydration and endothelial cell density were observed, the extent of which depended on the exposure time. Endothelial cell density negatively correlated with corneal thickness (r = -0.36; p = 0.042), indicating a depletion of the endothelial cell pool associated with an increase in corneal thickness. These changes were subclinical in nature and did not lead to significant pathological changes in the cornea (no signs of hyperreflectivity were observed on optical coherence tomography of the anterior segment). Thus, the safety of THz irradiation at a frequency of 2.3 THz within the range of used intensities and exposure durations was confirmed in vivo study.