Clinical comparison of air-puff and Goldmann tonometers

Intraocular pressures (IOPs) as measured with the Topcon CT-10, Reichert XPERT and NCT II, and Keeler PULSAIR air-puff tonometers were compared to the Goldmann IOPs for 452 eyes ranging in pressure from 6-40 mmHg. For eyes with pressures in the 10-20 mmHg range, the CT-10 read consistently too high. The XPERT and the NCT II read too high in the lower part of this range and too low in the higher part. The PULSAIR read too low across the entire range. At higher pressures, all of the tonometers read too high except the PULSAIR which again read too low. CT-10, XPERT, and NCT II and PULSAIR pressures were within 4.0 mmHg of Goldmann readings for 81, 85, 89 and 72 percent of the eyes, respectively. Subjects selected the XPERT as the most preferred tonometer and the NCT II was the least preferred mainly because of perceived air-puff intensity.