1. Department of Ophthalmology, University Hospital Principe de Asturias, Alcalá de Henares (Madrid), Spain
2. Department of Ophthalmology, University Hospital Principe de Asturias, Alcalá de Henares (Madrid), Spain 2Department of Ophthalmology, Faculty of Medicine, Alcalá University, Madrid, Spain
3. Department of Health and Sociomedical Sciences, Biostatistics Unit, Faculty of Medicine, Alcalá University, Madrid, Spain
4. Department of Preventive Medicine and Public Health, Faculty of Medicine, Rey Juan Carlos University, Alcorcón, Madrid, Spain