TY - JOUR T1 - Test–retest variability of intraocular pressure and ocular pulse amplitude for dynamic contour tonometry: a multicentre study JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 419 LP - 423 DO - 10.1136/bjo.2009.165142 VL - 94 IS - 4 AU - P Fogagnolo AU - M Figus AU - P Frezzotti AU - M Iester AU - F Oddone AU - M Zeppieri AU - A Ferreras AU - P Brusini AU - L Rossetti AU - N Orzalesi Y1 - 2010/04/01 UR - http://bjo.bmj.com/content/94/4/419.abstract N2 - 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. ER -