1. Department of Ophthalmology, MTI Khyber Teaching Hospital, Peshawar, Pakistan.
2. Cornea and Refractive Surgery Group, Singapore Eye Research Institute, Singapore, Singapore.
3. Department of Corneal and External Eye Disease, Singapore National Eye Centre, Singapore, Singapore.
4. Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.
5. Ocular Surface Group, Singapore Eye Research Institute, Singapore, Singapore.