Funding for this research was provided by:
National Natural Science Foundation of China (No. 81570917)
Article History
Received: 25 May 2018
Accepted: 18 December 2018
First Online: 2 January 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: All procedures performed in the present study involving human participants were approved by the medical ethics committee of the Eye, Ear, Nose & Throat Hospital and in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: All patients included in the study signed the informed consent. For this type of study formal consent is not required.