1. Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Canada
2. Wayne State School of Medicine, Wayne State University, Detroit, USA
3. Department of Ophthalmology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Canada
4. Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Canada