Received: 28 August 2018
Accepted: 29 January 2019
First Online: 4 February 2019
Ethics approval and consent to participate
: The ethics committee of the Keio University School of Medicine approved the protocol. Written informed consent was obtained from all participants.
: Not applicable.
: The authors have no financial or non-financial competing interests for this study. A patent application for the Eye Brush (Application number 2016–024394, Japan) may be applicable in the future (Dr. Kazuo Tsubota, Dr. Hirotaka Tanabe), but it is still in progress as of January 22, 2019.
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