Comparison of intraocular pressure measurements with the Reichert Pt100, the Keeler Pulsair Intellipuff portable noncontact tonometers, and Goldmann applanation tonometry.

PURPOSE

The aim of this study was to compare intraocular pressure (IOP) measurements using 2 portable tonometers, the Keeler Pulsair Intellipuff and the Reichert PT100, with Goldmann applanation tonometry (GAT).

MATERIALS AND METHODS

Prospective cross-sectional study was conducted on normotensive and hypertensive patients recruited from the outpatient clinic of the University Hospital of Grenoble. IOP was measured using 2 portable noncontact tonometers (NCTs) and GAT in one eye of each patient in a random order. Central corneal thickness was measured with the Accutome PachPen Pachymeter. The Wilcoxon and t tests were used to compare the differences between tonometers, the Pearson and the Spearman correlation tests to evaluate the correlation among the methods, and the Bland-Altman plots to evaluate the agreement among the methods. Intraclass correlation coefficient (ICC) was used to evaluate the agreement among the methods in normotensive and hypertensive patients separately.

RESULTS

A total of 137 eyes of 137 patients were included, 104 normotensive and 33 hypertensive eyes. We found an excellent agreement between PT100 and GAT (ICC=0.77) and between Intellipuff and GAT (ICC=0.75) in normotensive patients. We found a fair to good agreement (ICC=0.67) between PT100 and GAT in hypertensive patients. The agreement we found between Intellipuff and GAT was also excellent in hypertensive patients (ICC=0.86). Both NCTs significantly overestimated IOP measurements compared with GAT in normotensive and hypertensive eyes (mean of the differences between PT100 and

GAT

1.3±2.1 and 8.1±4.6 mm Hg in normotensive and in hypertensive patients, respectively (P<0.05), and between Pulsair Intellipuff and

GAT

1.5±1.8 and 2.3±4.8 mm Hg in normotensive and in hypertensive patients, respectively (P<0.05).

CONCLUSIONS

The 2 NCTs agree well with GAT in normotensive patients. The Pulsair Intellipuff also agrees well with GAT in hypertensive patients.