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A soft and transparent contact lens for the wireless quantitative monitoring of intraocular pressure

Abstract

Continuous detection of raised intraocular pressure (IOP) could benefit the monitoring of patients with glaucoma. Current contact lenses with embedded sensors for measuring IOP are rigid, bulky, partially block vision or are insufficiently sensitive. Here, we report the design and testing in volunteers of a soft and transparent contact lens for the quantitative monitoring of IOP in real time using a smartphone. The contact lens incorporates a strain sensor, a wireless antenna, capacitors, resistors, stretchable metal interconnects and an integrated circuit for wireless communication. In rabbits, the lens provided measurements that match those of a commercial tonometer. In ten human participants, the lens proved to be safe, and reliably provided accurate quantitative measurements of IOP without inducing inflammation.

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Fig. 1: Characterizing a strain sensor on a rigid–soft hybrid layer.
Fig. 2: Characterization of the stretchable NFC antenna using the AgNF–AgNW hybrid networks.
Fig. 3: Stretchable interconnections made using direct printing of a liquid metal.
Fig. 4: In vivo performance of the soft contact lens.
Fig. 5: Human study of the soft contact lens.

Data availability

The rabbit in vivo data are available at Figshare (https://doi.org/10.6084/m9.figshare.13289342)52. The human data are available within the paper and its Supplementary Information. The raw and analysed datasets generated for the studies shown in Figs. 13 are available for research purposes from the corresponding authors on reasonable request.

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Acknowledgements

This work was supported by the Ministry of Science & ICT (MSIT) and the Ministry of Trade, Industry and Energy (MOTIE) of Korea through the National Research Foundation (2019R1A2B5B03069358 and 2016R1A5A1009926), the Bio & Medical Technology Development Program (2018M3A9F1021649), the Nano Material Technology Development Program (2016M3A7B4910635) and the Technology Innovation Program (20010366 and 20013621, Center for Super Critical Material Industrial Technology). We also acknowledge financial support from the Institute for Basic Science (IBS-R026-D1), the Research Program (2019-22-0228) and the Post Doc Researcher Supporting program of 2019 (2019-12-0010) funded by Yonsei University.

Author information

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Authors

Contributions

Joohee Kim and J.P. carried out the experiments, analysed the data and wrote the manuscript. Y.-G.P. performed the experiments related to the printing of stretchable 3D interconnects. E.C. and M.K. performed the fabrication of contact lenses. H.S.A. participated in the design of stretchable antennas. K.-P.L. and M.-I.H. participated in the in vivo experiments. Junmo Kim and T.-S.K. performed the DIC experiments. D.W.K., H.K.K. and J.-U.P. oversaw all of the research phases and revised the manuscript. All of the authors discussed and commented on the manuscript.

Corresponding authors

Correspondence to Dai Woo Kim or Hong Kyun Kim or Jang-Ung Park.

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Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Biomedical Engineering thanks the anonymous reviewers for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Figs. 1–30 and Table 1, and captions for Supplementary Videos 1–3.

Reporting Summary

Supplementary Dataset

IOP data for the ten human volunteers.

Supplementary Video 1

In vivo trial of the soft contact lens for recording IOP.

Supplementary Video 2

In vivo test conducted using a live rabbit for monitoring the generation of heat during the wireless operation of the contact lens.

Supplementary Video 3

Human pilot trial of the soft contact lens.

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Kim, J., Park, J., Park, YG. et al. A soft and transparent contact lens for the wireless quantitative monitoring of intraocular pressure. Nat Biomed Eng 5, 772–782 (2021). https://doi.org/10.1038/s41551-021-00719-8

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