Ultrasonography

Abstract

Dedicated eye scanners employ a single transducer (frequency ~10 MHz) which is rocked through an angle at high speeds to produce a B-mode cross-sectional image of the eye and orbital structures in ‘real time’. The transducer is enclosed within a column of water or oil. The tip (footprint) of the enclosed column is placed either on the closed eyelid or, if the sensitivity of the system is poor, on the open anaesthetised eye. Such systems produce sector (trapezoidal format) images of the eye and orbit. If the resolution of anterior globe structures is poor on the dedicated scanner when used through a closed eyelid, a 3 mm-thick solid gel pad can be interposed between the probe face and the eyelid (available from Geistlich) to improve resolution anteriorly.