Tony Realini1, Brian McMillan, Ronald L Gross, Eva Devience, Goundappa K Balasubramani. 1. Department of Ophthalmology and Visual Sciences, West Virginia University, 1 Medical Center Drive, Morgantown, WV, 26506 Southern Eye Group, 3290 Dauphin Street #500, Mobile, AL, 36606 Mid-Atlantic Permanente Medical Group, 7141 Security Boulevard, Baltimore, MD, 21244 Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, 4420 Bayard Street, Suite 600, Pittsburgh, PA, 15260.
Abstract
PRECIS: In a trio of prospective studies, the iCare rebound tonometer demonstrated significantly lower test-retest variability than Goldmann tonometry with good inter-operator and inter-device reproducibility, supporting its value in monitoring intraocular pressure changes over time. PURPOSE: To characterize intra- and inter-operator and inter-device reliability of intraocular pressure (IOP) measurements with rebound tonometry ([RT], ic100, iCare USA, Inc, Raleigh, NC). METHODS: Three prospective cross-sectional studies were conducted in distinct sample of adult patients with established glaucoma, suspected glaucoma, or no glaucoma at the West Virginia University Eye Institute. Participants in study 1 underwent 5 RT measurements in one randomly-selected eye and 5 Goldmann tonometry measurements in the fellow eye by one operator; intra-operator variability was compared using the F test. In study 2, 3 operators each obtained 3 RT measurements in participants in randomized operator order. In study 3, a single operator collected 3 measurements each with 3 RTs in randomized device order. Between-operator and -device reproducibility were characterized using intraclass correlation coefficients (ICCs). RESULTS: Overall, 28, 19, and 25 subjects participated in the three respective studies. Within-subject variance across subjects was 0.757 in RT measurements and 2.471 in Goldmann measurements (P=0.0035). Inter-operator reproducibility of RT measurements was good in both eyes (ICC for right eyes 0.78, 95% confidence interval [CI] 0.60-0.85; ICC for left eyes 0.75, 95% CI 0.50-0.83). Inter-device reproducibility of RT measurements was good approaching excellent (ICC for right eyes 0.87, 95% CI 0.83-0.90; ICC for left eyes 0.89, 95% CI 0.86-0.91). CONCLUSIONS: The RT's lower measurement variability and good inter-operator and -device reproducibility suggest that it can characterize IOP changes over time more robustly than Goldmann tonometry, aiding clinicians in assessing the effectiveness of glaucoma therapy and the consistency of IOP control.
PRECIS: In a trio of prospective studies, the iCare rebound tonometer demonstrated significantly lower test-retest variability than Goldmann tonometry with good inter-operator and inter-device reproducibility, supporting its value in monitoring intraocular pressure changes over time. PURPOSE: To characterize intra- and inter-operator and inter-device reliability of intraocular pressure (IOP) measurements with rebound tonometry ([RT], ic100, iCare USA, Inc, Raleigh, NC). METHODS: Three prospective cross-sectional studies were conducted in distinct sample of adult patients with established glaucoma, suspected glaucoma, or no glaucoma at the West Virginia University Eye Institute. Participants in study 1 underwent 5 RT measurements in one randomly-selected eye and 5 Goldmann tonometry measurements in the fellow eye by one operator; intra-operator variability was compared using the F test. In study 2, 3 operators each obtained 3 RT measurements in participants in randomized operator order. In study 3, a single operator collected 3 measurements each with 3 RTs in randomized device order. Between-operator and -device reproducibility were characterized using intraclass correlation coefficients (ICCs). RESULTS: Overall, 28, 19, and 25 subjects participated in the three respective studies. Within-subject variance across subjects was 0.757 in RT measurements and 2.471 in Goldmann measurements (P=0.0035). Inter-operator reproducibility of RT measurements was good in both eyes (ICC for right eyes 0.78, 95% confidence interval [CI] 0.60-0.85; ICC for left eyes 0.75, 95% CI 0.50-0.83). Inter-device reproducibility of RT measurements was good approaching excellent (ICC for right eyes 0.87, 95% CI 0.83-0.90; ICC for left eyes 0.89, 95% CI 0.86-0.91). CONCLUSIONS: The RT's lower measurement variability and good inter-operator and -device reproducibility suggest that it can characterize IOP changes over time more robustly than Goldmann tonometry, aiding clinicians in assessing the effectiveness of glaucoma therapy and the consistency of IOP control.