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Performance of the PT100 noncontact tonometer in healthy eyes.

AlMubrad TM - Clin Ophthalmol (2011)

Bottom Line: These mean differences were not statistically significant (P > 0.05, paired t-test), with the PT100 underestimating IOP measurement by 1.00 mmHg.The PT100 noncontact tonometer produced greater repeatability than the GAT in assessment of IOP, whereas GAT resulted in more reproducible results.Both techniques showed a close level of agreement on comparison, with the PT100 underestimating IOP measurement by 1.0 mmHg only, although this was not clinically or statistically significant.

View Article: PubMed Central - PubMed

Affiliation: Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia. turkim@ksu.edu.sa

ABSTRACT

Background: The purpose of this study was to assess the repeatability and reproducibility of the PT100 noncontact tonometer and to compare its consistency with the Goldmann applanation tonometer (GAT) in measuring intraocular pressure (IOP).

Methods: Triplicate IOP measurements were obtained on two separate occasions using the PT100 and GAT from randomly selected eyes in 66 healthy volunteers aged 22 ± 1 years. The repeatability and reproducibility of each techniques was assessed. Agreement between the techniques was statistically quantified using intrasession repeatability for each technique as the basis for comparison.

Results: Both techniques returned equal IOP values in the first measurement session (15 ± 3 mmHg). The second session showed a mean difference in average IOP (1 ± 0.71). The 95% limits of agreement between the techniques were -5.2 to 5.5 mmHg and -4.0 to 4.7 mmHg (sessions 1 and 2, respectively). These mean differences were not statistically significant (P > 0.05, paired t-test), with the PT100 underestimating IOP measurement by 1.00 mmHg. The mean intrasession IOP for GAT sessions 1 and 2 was 0 ± 0.90 mmHg and 0.04 ± 1.06 mmHg, respectively, and the corresponding mean IOP measurement difference for the PT100 was -0.06 ± 0.96 and -0.39 ± 0.94 mmHg (sessions 1 and 2, respectively; P > 0.05, paired t-test). Repeatability coefficients for the GAT IOP measurements were 1.8 mmHg and 2.1 mmHg for sessions 1 and 2, while the PT100 repeatability coefficient was 1.9 mmHg and 1.8 mmHg for sessions 1 and 2, respectively. The intrasession repeatability coefficient of both techniques for test-retest differences were within ±5 mmHg.

Conclusion: The PT100 noncontact tonometer produced greater repeatability than the GAT in assessment of IOP, whereas GAT resulted in more reproducible results. Both techniques showed a close level of agreement on comparison, with the PT100 underestimating IOP measurement by 1.0 mmHg only, although this was not clinically or statistically significant. Of importance is that the IOP measurements using these techniques could be interchangeable in the IOP range studied here.

No MeSH data available.


Related in: MedlinePlus

Differences in IOP, measured in 1st and 2nd sessions, between the Goldmann tonometer and the PT100 noncontact tonometer plot against their average, with the mean difference and 95% limits of agreement depicted by the three lines.Abbreviation: IOP, intraocular pressure.
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f4-opth-5-661: Differences in IOP, measured in 1st and 2nd sessions, between the Goldmann tonometer and the PT100 noncontact tonometer plot against their average, with the mean difference and 95% limits of agreement depicted by the three lines.Abbreviation: IOP, intraocular pressure.

Mentions: The limits of agreement between the techniques are shown in Figure 4. The coefficient of agreement between the techniques was 7.5 mmHg for the first measurement session and 6.1 mmHg for the second measurement session. About 97.2% of the mean IOP measurements obtained by both instruments were in agreement by ≤3 mmHg on intersession analysis.


Performance of the PT100 noncontact tonometer in healthy eyes.

AlMubrad TM - Clin Ophthalmol (2011)

Differences in IOP, measured in 1st and 2nd sessions, between the Goldmann tonometer and the PT100 noncontact tonometer plot against their average, with the mean difference and 95% limits of agreement depicted by the three lines.Abbreviation: IOP, intraocular pressure.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104795&req=5

f4-opth-5-661: Differences in IOP, measured in 1st and 2nd sessions, between the Goldmann tonometer and the PT100 noncontact tonometer plot against their average, with the mean difference and 95% limits of agreement depicted by the three lines.Abbreviation: IOP, intraocular pressure.
Mentions: The limits of agreement between the techniques are shown in Figure 4. The coefficient of agreement between the techniques was 7.5 mmHg for the first measurement session and 6.1 mmHg for the second measurement session. About 97.2% of the mean IOP measurements obtained by both instruments were in agreement by ≤3 mmHg on intersession analysis.

Bottom Line: These mean differences were not statistically significant (P > 0.05, paired t-test), with the PT100 underestimating IOP measurement by 1.00 mmHg.The PT100 noncontact tonometer produced greater repeatability than the GAT in assessment of IOP, whereas GAT resulted in more reproducible results.Both techniques showed a close level of agreement on comparison, with the PT100 underestimating IOP measurement by 1.0 mmHg only, although this was not clinically or statistically significant.

View Article: PubMed Central - PubMed

Affiliation: Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia. turkim@ksu.edu.sa

ABSTRACT

Background: The purpose of this study was to assess the repeatability and reproducibility of the PT100 noncontact tonometer and to compare its consistency with the Goldmann applanation tonometer (GAT) in measuring intraocular pressure (IOP).

Methods: Triplicate IOP measurements were obtained on two separate occasions using the PT100 and GAT from randomly selected eyes in 66 healthy volunteers aged 22 ± 1 years. The repeatability and reproducibility of each techniques was assessed. Agreement between the techniques was statistically quantified using intrasession repeatability for each technique as the basis for comparison.

Results: Both techniques returned equal IOP values in the first measurement session (15 ± 3 mmHg). The second session showed a mean difference in average IOP (1 ± 0.71). The 95% limits of agreement between the techniques were -5.2 to 5.5 mmHg and -4.0 to 4.7 mmHg (sessions 1 and 2, respectively). These mean differences were not statistically significant (P > 0.05, paired t-test), with the PT100 underestimating IOP measurement by 1.00 mmHg. The mean intrasession IOP for GAT sessions 1 and 2 was 0 ± 0.90 mmHg and 0.04 ± 1.06 mmHg, respectively, and the corresponding mean IOP measurement difference for the PT100 was -0.06 ± 0.96 and -0.39 ± 0.94 mmHg (sessions 1 and 2, respectively; P > 0.05, paired t-test). Repeatability coefficients for the GAT IOP measurements were 1.8 mmHg and 2.1 mmHg for sessions 1 and 2, while the PT100 repeatability coefficient was 1.9 mmHg and 1.8 mmHg for sessions 1 and 2, respectively. The intrasession repeatability coefficient of both techniques for test-retest differences were within ±5 mmHg.

Conclusion: The PT100 noncontact tonometer produced greater repeatability than the GAT in assessment of IOP, whereas GAT resulted in more reproducible results. Both techniques showed a close level of agreement on comparison, with the PT100 underestimating IOP measurement by 1.0 mmHg only, although this was not clinically or statistically significant. Of importance is that the IOP measurements using these techniques could be interchangeable in the IOP range studied here.

No MeSH data available.


Related in: MedlinePlus