Abstract
Purpose: :
To compare the intraocular pressure (IOP) measurements by two portable tonometers, the Keeler Pulsair Intellipuff™ and the Reichert PT100™, with Goldmann applanation tonometry (GAT), and to evaluate the influence of central corneal thickness (CCT) on IOP measurements.
Methods: :
Prospective cross-sectional study conducted on normotensive and hypertensive patients recruited from the outpatient clinic of the University Hospital of Grenoble. IOP was measured by the Keeler Pulsair Intellipuff™, the Reichert PT100™ and GAT in one eye of each patient in a random order. CCT was measured with the Accutome PachPen pachymeter™. The Wilcoxon test was used to compare the differences between tonometers, the Spearman correlation test to evaluate the correlation among the methods, and Bland-Altman plots to evaluate the agreement among the methods.
Results: :
137 eyes of 137 patients were included. Measurements by the two non-contact tonometers were significantly correlated with GAT (Pulsair Intellipuff r = 0.92, p < 0.001; PT100 r = 0.92, p < 0.001). The agreement between the Pulsair Intellipuff™ and GAT was better than between the PT100™ and GAT (Pulsair Intellipuff - GAT: median of the difference, 1.6 mmHg; 10th percentile –1.3; 90th percentile, 4.1; PT100 - GAT: median of the difference, 1.6; 10th percentile –0.6; 90th percentile 9.3). The PT100™ more frequently significantly overestimated the IOP in cases of IOP > 20 mmHg, whereas the Pulsair Intellipuff™ did not (correlation between PT100 - GAT and the mean of PT100 and GAT, r = 0.57, p<0.0001; correlation between Pulsair Intellipuff - GAT and the mean of Pulsair Intellipuff and GAT, r = 0.06, p = 0.4). The differences between the measurements of the two non-contact tonometers and the GAT were significantly correlated to the central CCT (correlation between PT100 - GAT and CCT, r = 0.21, p = 0.01; correlation between Pulsair Intellipuff - GAT and CCT, r = 0.20, p = 0.02).
Conclusions: :
The Pulsair Intellipuff™ non-contact tonometer agrees significantly better with GAT than the PT100™ non-contact tonometer, particularly in hypertensive or glaucomatous patients. The Pulsair Intellipuff™ is a non-contact tonometer that can be considered for screening ocular hypertension and common measurement of IOP for follow-up.
Keywords: intraocular pressure • detection