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Abstract #26667 Published in IGR 12-3
Evaluation of a contact lens-embedded sensor for intraocular pressure measurement
Twa MD; Roberts CJ; Karol HJ; Mahmoud AM; Weber PA; Small RHJournal of Glaucoma 2010; 19: 382-390
Purpose: To evaluate a novel contact lens-embedded pressure sensor for continuous measurement of intraocular pressure (IOP). Methods: Repeated measurements of IOP and ocular pulse amplitude (OPA) were recorded in 12 eyes of 12 subjects in sitting and supine positions using 3 configurations of the dynamic contour tonometer: slit-lamp mounted (DCT), hand-held (HH), and contact lens-embedded sensor (CL). The IOP and OPA for each condition were compared using repeated measures ANOVA and the 95% limits of agreement were calculated. Results: The sitting IOP (mean and 95% CI) for each configuration was DCT: 16.3?mm Hg (15.6 to 17.1mm Hg), HH: 16.6?mm Hg (15.6 to 17.6?mm Hg), and CL: 15.7?mm Hg (15 to 16.3?mm Hg). The sitting OPA for each configuration was DCT: 2.4?mm Hg (2.1 to 2.6?mm Hg), HH: 2.4mm Hg (2.1 to 2.7?mm Hg), and CL: 2.1?mm Hg (1.8 to 2.3?mm Hg). Supine IOP and OPA measurements with the CL and HH sensors were both greater than their corresponding sitting measurements, but were significantly less with the CL sensor than the HH sensor. The mean difference and 95% Limits of Agreement were smallest for the DCT and CL sensor comparisons (0.7(plus or minus)3.9mm Hg) and widest for the CL and HH sensors (-1.9(plus or minus)7.25mm Hg); these wider limits were attributed to greater HH measurement variability. Conclusions: The CL sensor was comparable to HH and DCT sensors with sitting subjects and is a viable method for measuring IOP and OPA. Supine measurements of IOP and OPA were greater than sitting conditions and were comparatively lower with the CL sensor. HH measurements were more variable than CL measurements and this influenced the Limits of Agreement for both sitting and supine conditions.
R. H. Small. Department of Anesthesiology, Ohio State University, N411 Doan Hall, 410 W 10th Ave, Columbus, OH 43210, United States. robert.small@osumc.edu
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)