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Ultrasonography

Diane Chialant, RN, RDMS, COT, ROUB ; Nada Ukena, BSc, BA, COMT, ROUB ; Carla Barbery, BSc, COMT, ROUB

Advanced technology that uses imperceptible sound makes it possible for specialists to detect eye abnormalities they cannot see. As a probe transmits ultrasonic waves through the surface of the eye, sound wave patterns are converted to on-screen images that reveal the size and location of lesions.

Diagnostic ultrasonography is used in many branches of ophthalmology including external disease, glaucoma, retina and oculoplastics. The most common measurement required is that of the axial length of the eye in preparation for cataract surgery. Using this measurement in conjunction with the cornea’s curvature, surgeons can accurately calculate the corrective power of the intraocular lens needed to restore vision through implantation.

Ophthalmic ultrasound is particularly useful when the physician’s ability to examine the eye is impeded by dense cataracts, hemorrages resulting from diabetes or trauma, or other conditions that obstruct a clear view.

The Eye Institute recently acquired an Ultrasound Biomicroscopy Machine (UBM) that uses a much higher frequency than conventional ophthalmic ultrasound. The higher frequency enhances resolution to almost microscopic proportions, often revealing the type of lesion as well as its size and location. The new imaging capacity of the UBM may help ophthalmologists understand the mechanisms of various glaucomas and provide greater insight to anterior segment pathology.