Ultrasound backscatter microscopy of the eye in vivo

The construction and early clinical evaluation of the first 50-100-MHz ultrasound backscatter microscope (UBM) are described. This system has a frame rate of five frames per second and examined a field of view of 4 by 4 mm with axial and lateral resolution ranging from 20 to 50 mu m. The critical components of the scanner are described, including the transducer, motion system, and scan converter. Clinical studies were performed on 40 patients with varied ocular pathology. Each patient was examined with UBM using a water-bath technique similar to that used in conventional eye ultrasound. Microscopic images of the normal structures of the anterior segment including the cornea, iris, Schlemm's canal, ciliary body, and sclera are shown. Contrasting images of corneal pathology, tumors of the iris and ciliary body, and angle closure demonstrate the exceptional measurement capabilities of this imaging method. The potential of the UBM as a practical clinical instrument is discussed.<
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