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Abstract #12446 Published in IGR 7-2
Comparison of dynamic contour tonometry with goldman applanation tonometry over a wide range of central corneal thickness
Doyle A; Lachkar YJournal of Glaucoma 2005; 14: 288-292
See also comment(s) by Aachal Kotecha & David Garway-Heath •
PURPOSE: To compare dynamic contour tonometry with Goldmann applanation tonometry in structurally normal corneas over a wide range of central corneal thickness (CCT). PATIENTS AND METHODS: Twenty-five patients each with normal CCT (group A), thin corneas (group B), and thick corneas (group C) had IOP measured with the Goldmann (GAT) and dynamic contour tonometer (DCT). RESULTS: In group A (mean CCT = 552 ± 16 μm) the mean GAT was 15.9 ± 3.1 mmHg and mean DCT was 16 ± 3.3 mmHg (P = 0.91). In group B (mean CCT = 491 ± 19 μm) the mean GAT was 13.2 ± 3.5 mmHg and the mean DCT was 15.9 ± 3.5 mmHg (P = 0.009). For group C (mean CCT = 615 ± 22 μm), the mean GAT was 17.4 ± 3.8 mmHg and the mean DCT was 17.4 ± 3.5 mmHg (P = 0.95). The 95% agreement limits for DCT were -3.1 mmHg to 2.9 mmHg. The mean GAT-DCT difference was -2.6 mmHg in thin corneas and -0.06 mmHg in thick corneas. Below 520 μm reduction of 10 μm in CCT appears to result in a significant underestimation of the GAT IOP by 0.7 mmHg (P < .001) and above 580 μm a non-significant overestimation of 0.2 mmHg per 10 μm increase in CCT (P = 0.27). CONCLUSION: Dynamic contour tonometer agrees well on average with GAT but the agreement limits are wide. In structurally normal thin corneas DCT may give a more accurate assessment of the true IOP but it does not appear to have any benefit over GAT in thick corneas.
Dr. A. Doyle, Institut du Glaucome Fondation, Hôpital St. Joseph, Paris, France. aoife@fusio.net
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
