Use of the echogram in the location and diagnosis of intra-ocular foreign bodies.

IT is often difficult to locate an intra-ocular foreign body. Sometimes it may be seen and localized by biomicroscopy, ophthalmoscopy, gonioscopy, or diaphanoscopy. Yet radiological examination is necessary in every case, because the foreign body seen by the foregoing methods is not invariably the only one present in the eye. Although x-ray methods (Comberg, Dixon, Goldmann and Bangerter, Sweet, Vogt) are fairly safe, an error of as much as 2 mm. may occur so that in some cases it may be difficult to determine whether a foreign body in the vicinity of the posterior wall lies within the eye or outside it. Some foreign bodies, such as aluminium slivers, stones, wood chips, and glass splinters, cannot be clearly seen on the x-ray film, and ophthalmoscopy is not always helpful. Those foreign bodies, which it has been difficult or impossible to locate, may now be found by means of the echogram registered by ultrasound equipment. Oksala and Lehtinen (1957) and Baum and Greenwood (1958) found that ultrasonic waves could be used for locating intra-ocular foreign bodies, whether they were visible on the x-ray film or not. Oksala (1958) used both radiological and ultrasonic methods in diagnosis.