Received: 26 May 2020
Accepted: 22 July 2020
First Online: 31 July 2020
Ethics approval and consent to participate
: The study protocol was approved by the local ethics committee (P2019/204), and the informed written consent was waived for the retrospective design of the study.
: Not applicable
: FST received lecture fees from Neuroptics.The remaining authors declare that they have no competing interests to disclose.