Ophthalmic applications of laser-generated ultrasound

Laser-generated ultrasound has found a number of niche applications in non-destructive testing and evaluation and there is now a growing trend to examine potential applications for materials characterization in medicine. Conventional ultrasound techniques for measuring various important dimensions within the eye are in extensive use. However, one problem remains outstanding, which is that the dimensions of the cornea, anterior chamber and lens can be measured using a high frequency, high resolution transducer, but the dimensions of the overall eyeball (i.e., cornea to retina) have to be measured with a lower frequency transducer in order to achieve the necessary penetration. We have conducted a number of in vitro studies using bovine eyes to determine whether the use of laser induced ultrasound would be able to overcome the aforementioned problem. The results of these measurements will be presented, together with a discussion of the many difficulties that remain to be overcome. In addition, our studies involve the potential use of laser ultrasound to quantify the degree of cataract formation, both primary and secondary. This paper will also consider the work accomplished to data in this area.