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Abstract #26220 Published in IGR 12-2
Test-retest variability of intraocular pressure and ocular pulse amplitude for dynamic contour tonometry: a multicentre study
Fogagnolo P; Figus M; Frezzotti P; Iester M; Oddone F; Zeppieri M; Ferreras A; Brusini P; Rossetti L; Orzalesi NBritish Journal of Ophthalmology 2010; 94: 419-423
AIMS: To assess the test-retest variability of intraocular pressure (IOP) and ocular pulse amplitude (OPA) measurements utilising dynamic contour tonometry (DCT) and to evaluate possible influential factors. METHODS: The study included 350 consecutive subjects (175 glaucoma, 175 control; one eye per subject) from seven European centres. IOP was measured once with a Goldmann applanation tonometer (GAT) and twice by DCT (DCT1, DCT2) in a randomised sequence. OPA was also recorded for both DCT measurements. Differences (DCT1-DCT2; OPA1-OPA2; GAT-DCT1; GAT-DCT2) were assessed using the t test. The intraclass coefficient of correlation (ICC) and coefficient of variation (CoV) for DCT and OPA were calculated. RESULTS: DCT1 was 0.6+/-1.6 mm Hg higher than DCT2 (p<0.001); OPA1 was 0.1+/-0.7 mm Hg higher than OPA2 (p=0.02). Results were not influenced by randomisation test order. In both glaucoma and normal subjects, DCT and OPA showed ICC>0.90 and >0.76, and CoV=4.8-5.0% and 10.3-10.5%, respectively. DCT1 and 2 were 2.4+/-2.6 and 1.8+/-2.6 mm Hg higher respectively than GAT (p<0.001). DISCUSSION: DCT test-retest variability was almost perfect for IOP and good for OPA. Tonometry measurements with DCT tended to be overestimated compared with GAT.
GB Bietti Foundation-IRCCS, Rome, Italy. fogagnolopaolo@googlemail.com
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
