1. Department of Ophthalmology, Yan’an People’s Hospital, Qilipu St., Baota Qu, Yan’an, Shaanxi 716000, China
2. Pathology Unit, Preclinical Department, Faculty of Medicine, Royal College of Medicine Perak, Universiti Kuala Lumpur, No. 3, Jalan Greentown, Ipoh 30450, Perak Darul Ridzuan, Malaysia
3. Department of Ophthalmology, Yan’an University Affiliated Hospital, Yan’an, Shaan’xi Province 716000, China