1 Department of Ophthalmology, United Christian Hospital, Hong Kong; Department of Ophthalmology, Tseung Kwan O Hospital, Hong Kong; Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
2 Department of Ophthalmology, Queen Mary Hospital, Hong Kong.
3 Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
4 Department of Ophthalmology, United Christian Hospital, Hong Kong; Department of Ophthalmology, Tseung Kwan O Hospital, Hong Kong; Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong. Electronic address: kennethli@rcsed.ac.uk.