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Abstract #23378 Published in IGR 11-1
Comparison of dynamic contour tonometry and noncontact tonometry in ocular hypertension and glaucoma
Erdurmus M; Totan Y; Hepsen IF; Yagci REye 2009; 23: 663-668
PURPOSE: To assess the agreement in the measurement of intraocular pressure obtained by dynamic contour tonometer (DCT) and noncontact tonometer (NCT) in patients with glaucoma and ocular hypertension, to investigate the effect of corneal thickness on pressure readings by both instruments, and to assess the reproducibility of dynamic contour tonometer. METHODS: NCT and DCT measurements were made on 104 eyes of 104 patients with primary open-angle glaucoma (n=75) or ocular hypertension (n=29), and agreement was assessed by means of Bland-Altman plots. The effect of corneal thickness on both tonometers was assessed by linear regression analysis. Interobserver and intraobserver variations for dynamic contour tonometer were assessed in 41 eyes of 41 patients. RESULTS: The mean difference±SD (95% limits of agreement) between NCT and DCT was -0.80±2.98 (-6.6 to 5.1) mmHg (P=0.009) and no relation between NCT/DCT differences and average was found. The intraocular pressure readings obtained by noncontact tonometer depended on central corneal thickness (P<0.001, adjusted r2=0.301). However, dynamic contour tonometer readings showed no effect of corneal thickness (P=0.388, adjusted r2=-0.002). The coefficient of repeatability for DCT was 0.92 (95% CI 0.85-0.96, P=0.001). CONCLUSION: In subjects with primary open-angle glaucoma and ocular hypertension, NCT and DCT readings are not interchangeable. DCT measurements, unlike NCT measurements, did not depend on corneal thickness.
Dr. M. Erdurmus, Department of Ophthalmology, Fatih University Medical School, Ankara, Turkey
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
