1. Department of Optometry, Henan Medical College, Zhengzhou 451191, Henan, PR China
2. Department of Optometry, School of Medical Technology and Engineering, Zhengzhou Railway Polytechnic, Zhengzhou 451191, Henan, PR China
3. Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 451191, Henan, PR China
4. Department of Ophthalmology, Taian Branch, The 960th Hospital of PLA, Taian 271000, Shandong, PR China