Ultrasonographic examination of the painful equine eye

ULTRASONOGRAPHY is a non‐invasive diagnostic procedure that can be used to examine the equine optic globe, orbit and periocular tissues. In particular, ultrasonographic examination can provide valuable information that cannot be obtained by direct visualisation or the use of other diagnostic techniques when periocular swelling or opacity of the ocular media is present. Ultrasonography is also useful for assessing globe size and position. Given the location of the eye, the procedure is usually simple to perform and a systematic examination can be undertaken quickly, producing good‐quality images. However, an understanding of the normal sonographic appearance of the ocular and orbital tissues is of paramount importance to facilitate image interpretation. Painful conditions of the equine eye are encountered commonly in veterinary practice and ocular ultrasonography can be performed without the need for specialist equipment in a field or hospital setting, and findings can facilitate selection of appropriate treatment and allow meaningful prognostication. This article describes how to carry out ocular ultrasonography and discusses image interpretation, with particular reference to horses presenting with ocular pain.