Measurements of intraocular pressure made with multiple noncontact tonometers

Intraocular pressure measurements were made on 30 normal eyes using seven noncontact tonometers. The instruments were from 4 to 8 years old. Results show that pressures indicated by most noncontact tonometers are not significantly different. In the most extreme case, differences in mean pressures of 3.48 mm Hg were obtained. A difference of this magnitude may be important when following a patient over a period of time, and could be the result of measurements being made on a different tonometer.