Wu, Min
Hu, Zhu Lin
He, Dan
Xu, Wen Rong
Li, Yan
Funding for this research was provided by:
Sight First China Action Project (SFCA-26-2013-01)
Article History
Received: 28 February 2017
Accepted: 3 April 2018
First Online: 17 April 2018
Ethics approval and consent to participate
: This study adheres to the tenets of the Declaration of Helsinki and was approved by the the Ethical Committee of The 2nd People’s Hospital of Yunnan Province, China. During the survey, informed consent was given by every adult and the parents of all enrolled children.
: The authors declare that they have no competing interests.
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