advertisement
Abstract #21376 Published in IGR 10-2
Dynamic contour tonometry in comparison to intracameral IOP measurements
Boehm AG; Weber A; Pillunat LE; Koch R; Spoerl EInvestigative Ophthalmology and Visual Science 2008; 49: 2472-2477
PURPOSE: The purpose of the study was to examine the effect of central corneal thickness (CCT), corneal curvature, astigmatism, axial length (AL), and age on measurements with the Pascal dynamic contour tonometer (DCT). METHODS: In a prospective clinical trial 75 eyes of 75 patients undergoing phacoemulsification were examined. Before phacoemulsification, the anterior chamber was cannulated at the temporal corneal limbus. In a closed system the IOP was directly set to 15, 20, or 35 mmHg with a manometric water column. IOP measurements taken by DCT were compared to intracameral measurements with a precision reference pressure sensor. RESULTS: Measurements from 60 patients were suitable for statistical analysis. At IOP of 15 mmHg, the mean difference between IOP measured by DCT and intracameral IOP was -0.02 ± 1.32 mmHg; at 20 mmHg it was -0.2 ± 1.44 mmHg and at 35 mmHg, -0.84 ± 1.90 mmHg. The concordance coefficient according to Lin was 0.9763, showing good agreement between DCT- and intracamerally measured IOP. There was a statistically significant correlation between the difference in IOP measured by DCT minus intracameral IOP and CCT (P = 0.0291, R2 = 0.00012). All other parameters had no statistically significant effect on the difference between DCT and intracameral IOP (corneal curvature, P = 0.6094, R2 = 0.00367; age, P = 0.9198, R2 = 0.000003; astigmatism, P = 0.1564, R2 = 0.08497; and axial length, P = 0.9484, R2 = 0.00008). CONCLUSIONS: Measurements with the DCT showed good concordance with intracameral IOP. CCT exerted a statistically significant but clinically irrelevant effect on measurements with the DCT.
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
