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Updated: Jul 13, 2026
Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
[What should we think? Is pneumotonometry still reliable?]
H Bresson-Dumont1, A Lehoux, C Kponoume
1Clinique Sourdille, 8, rue Camille-Flammarion, 44000 Nantes, France.
Unlabelled:
Noncontact tonometer (NCT) is an applanation tonometry, as is Goldmann tonometry. Numerous studies have shown the reliability of this technique but problems still exist.
Method:
We measured intraocular pressure (IOP) in 340 patients (668 eyes) with NCT and Goldmann tonometer (GAT). To evaluate the influence of central corneal thickness (CCT), we classified the patients according to their CCT (<500 microm; between 520 and 580 microm, and>600 microm).
Results:
The mean difference between the two IOP measurements was -1.4 mmHg +/- 2.67 (-12 to +7), p<0,0001 for the thinner corneas, +0.13 mmHg +/- 2.67 (-8 to +8), p=0.445 for the regular corneas, and + 3.04 mmHg +/- 3.2 (-7 to +13) p<0.0001 for the thicker corneas. CCT influences NCT and GAT, but the difference between the two techniques is higher for thicker CCTs, higher IOPs, and in younger patients.
Conclusion:
NCT is good for glaucoma screening but is less reliable than GAT for glaucoma follow-up if CCT and IOP are far from regular values.
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