1. Department of Ophthalmology, He Eye Specialist Hospital, Shenyang, China.
2. Department of Ophthalmology, Dalian Medical University, Dalian, China.
3. Department of Ophthalmology, Tianjin Medical University, Tianjin, China.
4. School of Mathematics and Statistics, University of St Andrews, St Andrews, United Kingdom.
5. School of Mathematics and Physics, Queens University Belfast, Belfast, United Kingdom.
6. Department of Ophthalmology, Cathedral Eye Clinic, Belfast, United Kingdom.