[Comparative intraocular pressure measurements with position independent hand-applanatation tonometers (author's transl)].

A study of comparative intraocular pressure measurements was made using the hand-held applanation tonometers of Perkins and Draeger in the sitting and lying patient. A series of 100 patients was investigated by two observers taking the pressures with both tonometers under blind conditions. The statistical evaluation of the data revealed an average pressure increment when lying down of 2.5 to 3 mm Hg for both observers and both tonometers. This postural response is fully reversible when getting up and an overshoot-phenomenon statistically significant is noted. The pressure increment when lying down is not related to initial pressure level and there is no clear relationship to the age of the patients tested. Interobserver variation as well as variations of both tonometers are evaluated. The effect of repeated tonometry in this study is considered. Some aspects of position influence on the intraocular pressure are discussed.