Examinations of ultrasonic radiation with a Schlieren optical system have demonstrated that the characteristics of ultrasonic beams can be significantly altered by acoustic phenomena which occur in lens and sclera. The magnitude of these alterations is critically dependent upon the position and orientation of the incident ultasonic beam. Both diagnostic and therapeutic piezoelectric transducers, operating at frequencies between 1 and 10 megahertz, were employed in this study. Transmission of ultrasound through bovine lenses is accompanied by shifts in the central axis, alterations in the width, and lower intensities in the transmitted beam. Transmission through samples of bovine sclera results in significant alterations in beam characteristics only when the central axis of the incident beam is nearly tangent to the scleral surface.
Lizzi FL, Burt WJ, Coleman DJ. Effects of Ocular Structures on Propagation of Ultrasound in the Eye. Arch Ophthalmol. 1970;84(5):635-640. doi:10.1001/archopht.1970.00990040637016