A new study published in the Journal of Biomedical Optics has proposed a novel method for measuring the biomechanical properties of the eye.
Give me some background first.
The eye is a complex and sensitive organ, and ocular disease can change the biomechanical properties of the eye—such as in one well-known example, keratoconus, a disease that causes distinct regional changes throughout the cornea.
How are these changes measured?
Most existing ways of measuring these changes can present challenges in practice—the most common, MRI, is plagued by movement-induced errors and high operating costs.
Reverberant optical coherence elastography (RevOCE) is a high-resolution technique that can measure these properties, but depends on the presence of shear wave fields in the tissue, which must be carefully induced in delicate ocular tissues.
Now talk about the study.
A University of Houston research team developed a multifocal acoustic radiation force (ARF) system with an array of acoustic lenses and used an ultrasound transducer as an excitation source.
The system was used to induce a reverberant shear wave field in mouse eyes, which was then imaged with phase-sensitive optical coherence tomography (PhS-OCT).
Findings?
Each ocular structure measured—cornea, iris, sclera, lens, and retina—had its own wave speed, enabling the researchers to build a speed map of the eyeball.
Go on…
These speed maps change with the relative stiffness of the tissue, meaning that they could potentially be used to diagnose and track the progression of ocular disease.
Limitations?
Right now, the researchers do not have a way to perform these measurements in vivo, because the ARF system and the OCT lens had to be positioned on opposite sides of the eye.
The study authors have identified this roadblock as a focus for future research.
Take home.
While it’s not likely that you’ll see RevOCE in your clinic anytime soon, this study offers an exciting possibility for future diagnostic capabilities for ocular disease—not to mention the potential for new and more thorough ways of understanding aging and developing more precise methods for targeted treatments.