1. The Division of Ophthalmology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
2. The Department of Ophthalmology, Istanbul University, Istanbul, Turkey
3. Eye Protection Foundation, Eye Department, Bayrampasa Eye Hospital, Istanbul, Turkey
4. The Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
5. The Department of Epidemiology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA