Funding for this research was provided by:
Olivia's Vision Charity
Text and Data Mining valid from 2019-06-12
Received: 7 May 2019
Accepted: 14 May 2019
First Online: 12 June 2019
Compliance with ethical standards
: TB is part-funded by patient charity Olivia’s Vision and is a Cochrane Eyes and Vision Contact Editor. The remaining authors declare that they have no conflict of interest.