1. Salus University; Elkins Park Pennsylvania USA
2. College of Optometry; The Ohio State University; Columbus Ohio USA
3. Southern California College of Optometry; Fullerton California USA
4. Centre for Applied Vision Research, School of Health Sciences; City University of London; London UK
5. Department of Epidemiology; Johns Hopkins Bloomberg School of Public Health; Baltimore Maryland USA
6. Department of Ophthalmology; University of Colorado Denver Anschutz Medical Campus; Aurora CO USA