Affiliation: | 1. Alcorcon Foundation University Hospital Ophthalmology Unit, , Madrid, Spain;2. Pontificia Universidad Católica de Valparaíso, , Chile;3. Health Sciences Faculty, European University of Madrid, , Madrid, Spain;4. Rey Juan Carlos Hospital Preventative Medicine Unit, , Madrid, Spain;5. Medical Library Service, Alcorcon Foundation University Hospital, , Madrid, Spain |