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Evaluation of a new portable corneal topography system for self-measurement using smartphones: a pilot study

  • Cornea
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Abstract

Purpose

Herein, we propose the use of the “KeraVio Ring”, which is a portable, selfie-based, smartphone-attached corneal topography system that is based on the Placido ring videokeratoscope. The goal of this study was to evaluate and compare corneal parameters between KeraVio Ring and conventional corneal tomography images.

Methods

We designed the KeraVio Ring as a device comprising 3D-printed LED rings for generating Placido rings that can be attached to a smartphone. Two LED rings are attached to a cone-shaped device, and both corneas are illuminated. Selfies were taken using the KeraVio Ring attached to the smartphone without assistance from any of the examiners. Captured Placido rings on the cornea were analysed by intelligent software to calculate corneal parameters. Patients with normal, keratoconus, or LASIK-treated eyes were included. Anterior segment optical coherence tomography (AS-OCT) was also performed for each subject.

Results

We found highly significant correlations between the steepest and flattest keratometry, corneal astigmatism, and vector components obtained with the KeraVio Ring and AS-OCT. In subjects with normal, keratoconus, and LASIK-treated eyes, the mean difference in corneal astigmatism between the two devices was -0.8 ± 1.4 diopters (D) (95% limits of agreement (LoA), -3.6 to 2.0), -1.8 ± 3.7 D (95% LoA, -9.1 to 5.5), and -1.5 ± 1.3 D (95% LoA, -4.0 to 1.1), respectively.

Conclusions

The experimental results showed that the corneal parameters obtained by the KeraVio Ring were correlated with those obtained with AS-OCT. The KeraVio Ring has the potential to address an unmet need by providing a tool for portable selfie-based corneal topography.

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Data availability

Data are available upon reasonable request.

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Funding

This study was funded by a project subsidized by the Tokyo Metropolitan Small and Medium Enterprise Support Center (grant number: N/A).

Author information

Authors and Affiliations

  1. Tsubota Laboratory, Inc., Tokyo, Japan

    Hidenaga Kobashi & Kazuo Tsubota

  2. Department of Ophthalmology, Keio University, School of Medicine, Tokyo, Japan

    Hidenaga Kobashi & Kazuo Tsubota

  3. Ebina-Ekimae Eye Clinic, Kanagawa, Japan

    Hidenaga Kobashi

  4. Dentsu ScienceJam, Inc., Tokyo, Japan

    Shunsuke Aoki

  5. Stratasys Japan Co., Ltd., Tokyo, Japan

    Masaaki Kobayashi

  6. Department of System Design Engineering, Faculty of Science and Technology, Keio University, Kanagawa, Tokyo, Japan

    Brian Sumali & Yasue Mitsukura

Authors
  1. Hidenaga Kobashi
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  2. Kazuo Tsubota
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  3. Shunsuke Aoki
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  4. Masaaki Kobayashi
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  5. Brian Sumali
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  6. Yasue Mitsukura
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Contributions

HK and KT conceived and designed the study. HK, BS, and YM provided patients. HK and BS collected the data and performed the statistical analysis. HK, SA, MK, and KT performed the literature search and interpreted the data. HK, BS, and YM wrote the manuscript.

Corresponding author

Correspondence to Hidenaga Kobashi.

Ethics declarations

Ethical approval

All procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the ethics committee of Keio University (No. 2021–105).

Informed consent

Informed consent was obtained from all individual participants included in the study.

Conflicts of interest

Dr. Kobashi is a consultant to Tsubota Laboratory, Inc., and has a patent regarding the mentioned device. Dr. Tsubota is the CEO and has a patent regarding the device. The other authors declare that they have no competing interests.

Disclaimer

The sponsor had no role in the study design; data collection, analysis or interpretation; writing of the report; or the decision to submit the article for publication.

Provenance and peer review

Not commissioned; externally peer reviewed.

Additional information

Meeting presentation

This study has been presented as a free paper at the Annual Meeting of Association for Research in Vision and Ophthalmology, New Orleans, 2023.

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Cite this article

Kobashi, H., Tsubota, K., Aoki, S. et al. Evaluation of a new portable corneal topography system for self-measurement using smartphones: a pilot study. Graefes Arch Clin Exp Ophthalmol (2024). https://doi.org/10.1007/s00417-024-06426-9

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  • DOI: https://doi.org/10.1007/s00417-024-06426-9

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