Submitted for Publication: April 27, 2013; final revision received December 18, 2013; accepted December 19, 2013.
Published Online: April 3, 2014. doi:10.1001/jamaophthalmol.2014.148.
Study concept and design: Korn, Li.
Acquisition, analysis, and interpretation of data: Hou, Korn, Ding.
Drafting of the manuscript: Hou, Ding.
Critical revision of the manuscript for important intellectual content: Korn, Li.
Administrative, technical, or material support: Korn, Ding, Li.
Study supervision: Li.
Conflict of Interest Disclosures: None reported.
Funding/Support: The authors received financial support from grant Z131107002213002 from the Beijing Municipal Science & Technology Commission.
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; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.