A noninvasive ultrasound vibro-elastography technique for assessing ocular lesions

This research aims to develop a noninvasive ultrasound vibro-elastography technique for assessing ocular lesions including intraocular melanoma and nevus lesions.

Wave speed (WS) was noninvasively measured in the lesions at three different frequencies (i.e., 100 Hz, 150 Hz, and 200 Hz). The nearby normal tissue of choroid and sclera was also analyzed as controls. Viscoelasticity of these tissues was analyzed using the wave speed dispersion curve and the Voigt model.

In this pilot study of 10 cases (5 melanomas vs. 5 nevus) with ages (mean ± SD) of (53.2 ± 6.82) vs. (72.2 ± 7.71) yo, the WS (m/s), elasticity (kPa) and viscosity (Pa.s) of lesion (melanoma vs. nevus) locations of the eye (i.e., WS @100 Hz: 3.63 vs. 3.09 (m/s), @150 Hz: 4.10 vs. 3.66 (m/s), @200 Hz: 4.78 vs. 4.07 (m/s); elasticity: 9.59 vs. 6.89 (kPa); viscosity: 12.46 vs. 9.26(Pa.s)) were analyzed. There were significant differences of WS ratio (WS close to the surface and WS inside the tumor) between the nevus and melanoma of all three frequencies (i.e., nevus vs. melanoma; @100 Hz: 1.59 vs. 2.95, p = 0.0285; @150 Hz: 1.58 vs. 3.53, p = 0.0054; @200 Hz: 1.70 vs. 3.31, p = 0.0124). The melanoma lesions are stiffer than the nevus lesions. It also shows that the lesion tissues are stiffer than the control tissues. However, there were no significant differences in WS, elasticity, viscosity among melanoma lesions, nevus lesions, and control tissues.

We demonstrate for the first time that noninvasive ultrasound vibro-elastography can be used for assessing ocular lesions. The results show that lesion tissues are stiffer than control tissues. They also show that melanoma lesions are stiffer than the nevus lesions. We plan to study more ocular lesion patients and improve the specificity and sensitivity of wave speed or viscoelasticity between lesions and controls.

Ultrasound vibro-elastography is an innovative and noninvasive technique for assessing ocular lesions.