1. Department of Mathematical Sciences, School of Science, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
2. Department of Applied Mathematics and Statistics, Stony Brook University, New York, USA
3. Department of Statistics and Applied Probability, National University of Singapore, Duke University-NUS Graduate Medical School, Singapore Eye Research Institute, Singapore, Singapore
4. Duke University-NUS Graduate Medical School, Singapore, Singapore
5. Singapore Eye Research Institute, Singapore, Singapore