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[What should we think? Is pneumotonometry still reliable?].
H Bresson-Dumont1, A Lehoux, C Kponoume
1Clinique Sourdille, 8, rue Camille-Flammarion, 44000 Nantes, France.
Journal Francais D'Ophtalmologie
|October 5, 2007
Summary
Noncontact tonometer (NCT) shows reliability but differs from Goldmann tonometry (GAT) based on central corneal thickness (CCT). NCT is less reliable for glaucoma follow-up with atypical CCT or intraocular pressure (IOP).
Area of Science:
- Ophthalmology
- Biomedical Engineering
Background:
- Noncontact tonometer (NCT) and Goldmann tonometer (GAT) are applanation tonometry methods.
- While NCT is widely studied for reliability, discrepancies in intraocular pressure (IOP) measurements persist.
Purpose of the Study:
- To compare IOP measurements between NCT and GAT.
- To investigate the influence of central corneal thickness (CCT) on the agreement between NCT and GAT.
Main Methods:
- Intraocular pressure (IOP) was measured in 340 patients (668 eyes) using both NCT and GAT.
- Patients were categorized into three groups based on CCT: <500 microm, 520-580 microm, and >600 microm.
Main Results:
- The mean difference between NCT and GAT varied significantly with CCT.
- Differences were -1.4 mmHg for thinner corneas, +0.13 mmHg for regular corneas, and +3.04 mmHg for thicker corneas.
- CCT, higher IOPs, and younger age influenced the discrepancy between NCT and GAT.
Conclusions:
- Noncontact tonometer (NCT) is suitable for initial glaucoma screening.
- Goldmann tonometer (GAT) demonstrates greater reliability for glaucoma follow-up, especially when CCT and IOP deviate from normal ranges.
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