A and B scan echography does not allow to measure separately the thickness of the three ocular layers, retina, choroid and sclera. This, however, is possible by radiofrequency signals. 48 eyes of normal subjects and 21 eyes of patient suffering from chronic glaucoma with ocular hypertension from 30 to 45 mm Hg were examined. The thickness of the retina and sclera was equal in the two groups, whereas the thickness of the choroid in the glaucomatous eyes showed an increase of 20% as compared with normal eyes.