Submitted for Publication: February 24, 2012; final revision received June 5, 2012; accepted August 7, 2012.
Published Online: June 13, 2013. doi:10.1001/jamaophthalmol.2013.644.
Acquisition of data: Afifi, Azeem, Gheith, Rizk.
Analysis and interpretation of data: Afifi, Azeem, Bateman.
Drafting of the manuscript: Bateman.
Critical revision of the manuscript for important intellectual content: Afifi, Azeem, El-Bassyouni, Gheith, Rizk.
Administrative, technical, and material support: Afifi, El-Bassyouni.
Study supervision: Afifi, Azeem, Rizk.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study did not have specific financial support aside from professional salaries (Dr Bateman was not salaried).
Additional Contributions: The statistician, Manal H. Abu EL Ela, MD, Public Health Department, Research Institute of Ophthalmology, Cairo, provided assistance.