Use of 2D-Shear Wave Elastography for the Evaluation of Lens in Horses.

Abstract

Although lens diseases are uncommon in horses, they can be disabling in advanced stages. The B-mode ultrasound is useful for diagnosing and monitoring the progression of ocular diseases such as cataracts. Elastography is an ultrasonographic technique that allows the detection and measurement of tissue stiffness. This observational cohort prospective study aimed to determine the feasibility, reproducibility, and repeatability of 2D-shear wave elastography (2D-SWE) of lenses in horses. Forty-six eyes of 23 horses with no evidence of ocular disease were included in this study. The horses underwent an ophthalmic examination to ensure that they were healthy. After the B-mode ultrasound examination, 2D-SWE was performed by two operators with different levels of experience in diagnostic imaging. Elastographic images were independently analyzed quantitatively by two observers by measuring the shear wave velocity (m/s) and Young's modulus (kPa). Considering both right and left eyes, the mean shear wave velocity was 4.08 ± 0.71 m/s, and the mean Young's modulus was 51.30 ± 19.02 kPa. Interoperator and intraoperator agreements were excellent. The intra-observer agreement was good, with only one value for each observer that presented statistically significant differences. No statistically significant differences were observed between the right and left eyes. The excellent reliability, reproducibility, and good repeatability between evaluators make 2D-SWE a practical and reproducible technique that can be applied in clinical settings, where different sonographers often obtain images on multiple separate occasions. Our findings support the future clinical application of 2D-SW elastography as a noninvasive imaging modality for normal lens evaluation in horses.