Postural Tonographic Test for the Early Diagnosis of Glaucoma.

AMONG the various tests used in the early diagnosis of glaucoma the so-called provocative tests occupy an important place. Numerous tests have been proposed, but their reliability on a statistical basis has only been studied in the case of some tests. Not all of these have given clinically satisfactory results, either on account of the variability of their results or of the inconvenience their application causes to the patient. It is considered that provocative tests have a high diagnostic importance, while the relatively small number of statistically reliable and clinically satisfactory tests makes any contribution to the subject of great interest. During a tonographic study on normal subjects to determine variations of intraocular pressure, the outflow facility, and the aqueous production in various positions of the body, we were able to show that the inclined head-and-body-downward position (-25°) can induce a small but significant increase in ocular tension and a decrease in outflow facility (Boles Carenini and Molfino, 1961). Similar responses, but of greater degree, were found in glaucomatous subjects and in those patients in whom the characteristic changes of aqueous humour dynamics were beginning (K6llner, 1916; Tessier, 1930 a and b; Stroble and Follmann, 1936; and Scharf, 1952). For this reason some authors have suggested a study of the variations of intraocular pressure with varying positions of the body as a test for glaucoma (Kollner, 1916; Thibert, 1922; Thiel, 1925; Wegner, 1925; Stroble and Follmann, 1936; Caselli, 1954; Komoto, 1954; and Ebisawa, 1956). Others, although confirming tonometric variations (Leydhecker and Meinke, 1956), have denied their value in diagnosis (Leydhecker, 1955). The purpose of the present research is to determine whether the tonographic findings in patients in the inclined head-downward position (Trendelenburg -25°) would constitute a reliable test, showing variations of both the ocular tension and the outflow facility. Before applying a provocative test it is necessary to study the reactions of the normal eye to the same test and to define the limits of the tensional increase caused by the test.