1. Private practice, Ophthalmology, Via Antonio Ciseri 13; CH-6600 Locarno Switzerland
2. Johns Hopkins Bloomberg School of Public Health; Department of Epidemiology; 615 North Wolfe Street, Mail Room E6132 Baltimore Maryland USA 21205
3. Wilmer Eye Institute, Johns Hopkins University School of Medicine; Department of Ophthalmology; 4924 Campbell Blvd #100 Baltimore Maryland USA 21236
4. Johns Hopkins University School of Medicine; Wilmer Ophthalmological Institute; 600 N. Wolfe St., Wilmer B-20 Baltimore Maryland USA 21287