Submitted for Publication: March 26, 2013; final revision received May 13, 2013; accepted May 18, 2013.
Published Online: October 31, 2013. doi:10.1001/jamaophthalmol.2013.5521.
Study concept and design: All authors.
Acquisition of data: All authors.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: All authors.
Administrative, technical, or material support: All authors.
Study supervision: Denniston.
Conflict of Interest Disclosures: None reported.
Funding/Support: The Academic Unit of Ophthalmology is supported by the Birmingham Eye Foundation (UK Registered Charity 257549). Dr Edmunds is funded by the Wellcome Trust.
Role of the Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.