[Possibilities and limits of echographic examination of retinal detachment before and after surgery].

Ultrasonography can provide priceless information about a retinal detachment when the fundus is invisible because of a cataract or an unclear vitreous. The exploration of an eye with A-scan ultrasonography is a long and careful procedure which is made step by step along the meridians, then along the parallels of the eyeball. Quantitative ultrasonography is necessary to separate the echoes of the vitreous opacities and of the detached retina. The B-scan gives the same information - except the biometric data - in a much shorter time and is now available without the interposition of water between the patient and the probe. It also permits an easy diagnosis of the choroidal detachment. After the operation, when the media are not clear, A-and B-scan ultrasonography can give an early indication of whether the retina is reattached or not. But at that time a mistake may be made due to the edge of buckling and everyone should be aware of this.