1 Department of Ophthalmology, Anhui Province Children's Hospital, Hefei, Anhui 230022, China.
2 Department of Ophthalmology, Beijing Children's Hospital affiliated to Capital Medical University, National Center for Children's Health, Beijing 100045, China.
3 Department of Strabismus and Pediatric Ophthalmology, Tianjin Eye Hospital, Tianjin 300020, China.