Research Overview
Use of ultrasound for diagnosis and treatment of ocular diseases
Dr. Silvermans interdisciplinary research involves the development and application of ultrasound systems for imaging and therapy. Specific projects include: Ultrasound biomicroscopy of ocular tissues: This work involves the use of high frequency ultrasound (30-80 MHz), which provides exquisite resolution for imaging the anterior segment structures of the eye (cornea, ciliary body, iris), even in the presence of optical opacities. Precision corneal imaging and biometric analysis: Ultrasound biomicroscopic data acquired in 3D scans of the cornea are analyzed to measure and map the thickness of its constituent layers. Of particular interest are alterations occurring after refractive surgery and in diseases such as keratoconus, which this technique may offer early diagnosis. Ultrasound tissue characterization: Measurement of the dependence of signal amplitude over a range of frequencies provides information related to tissue microstructure. We are investigating the use of this methodology for characterizing tumors and other ocular tissues. Pulse-encoding: We are investigating the use of chirp and other encoded waveforms to enhance diagnostic ultrasound signals. Of particular interest is the use of this technique to enhance sensitivity for detection of changes in the vitreous that occur in diseases such as diabetes and retinopathy of prematurity. Photoacoustic imaging: Conventional ultrasound imaging detects density variation in tissues. Photoacoustic imaging is a hybrid technique in which a laser pulse directed into a tissue causes generation of ultrasound waves that are then detected and imaged. In this case, optical absorption is images. We are developing photoacoustic systems for imaging the eye and other superficial tissues. This technique may offer a unique new diagnostic modality. Ultrasound-enhanced drug delivery: We are investigating the potential of ultrasound waves to make the eye temporarily more permeable so that medications that can currently only be delivered by injection might enter the eye without injection.
