Purpose: To evaluate the utility of the new Rebound tonometer for measuring intraocular pressure (IOP) in an unanesthetized eye; to test patient tolerance, measurement time, and accuracy compared with the Pulsair 3000 tonometer.
Methods: IOP was measured with the Rebound tonometer and the Pulsair 3000 tonometer without an anesthetic in 131 residents of two Finnish nursing homes. The measurement time and possible pain or discomfort experienced by the inhabitants was recorded.
Results: The mean differences in IOP readings between the two tonometers were 0.31 mmHg, SD 2.45 mmHg for the right eyes and 0.36 mmHg, SD 2.17 mmHg for the left eyes (P=0.28, multivariate analysis). The correlation constants between the tonometers were 0.84 (right eyes) and 0.80 (left eyes). The Pulsair 3000 caused more discomfort than the Rebound tonometer (36% vs 15%, P=0.01). With the Pulsair, 85%, and with the Rebound tonometer, 95% of the patients felt no pain ( P= 0.14). Measurement of both eyes with the Rebound tonometer took less time (55+/-22 s vs 138+/-55 s, P<0.001). The mean difference was 82 s and the 95% confidence interval of the difference was 66-98 s.
Conclusion: Measurement of IOP with the Rebound tonometer without an anesthetic is a rapid and well-tolerated procedure. IOP readings of the two tonometers were within +/-1 mmHg in 52.5% of the measurements and within +/-2 mmHg in 71.7% of the measurements.