1. The Third Department of Vitreoretinal, Tianjin Eye Hospital, Tianjin, P.R. China.
2. Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, P.R. China.
3. Department of Ophthalmology, Linxia State People Hospital of Gansu Province, Linxia, P.R. China.