title: Validation of the automatic image analyser to assess retinal vessel calibre (ALTAIR): a prospective study protocol.
abstract: BACKGROUND
  The fundus examination is a non-invasive evaluation of the microcirculation of the retina. The aim of the present study is to develop and validate (reliability and validity) the ALTAIR software platform (Automatic image analyser to assess retinal vessel calibre) in order to analyse its utility in different clinical environments.
  
  
  METHODS
  A cross-sectional study in the first phase and a prospective observational study in the second with 4 years of follow-up. The study will be performed in a primary care centre and will include 386 participants. The main measurements will include carotid intima-media thickness, pulse wave velocity by Sphygmocor, cardio-ankle vascular index through the VASERA VS-1500, cardiac evaluation by a digital ECG and renal injury by microalbuminuria and glomerular filtration. The retinal vascular evaluation will be performed using a TOPCON TRCNW200 non-mydriatic retinal camera to obtain digital images of the retina, and the developed software (ALTAIR) will be used to automatically calculate the calibre of the retinal vessels, the vascularised area and the branching pattern. For software validation, the intraobserver and interobserver reliability, the concurrent validity of the vascular structure and function, as well as the association between the estimated retinal parameters and the evolution or onset of new lesions in the target organs or cardiovascular diseases will be examined.
  
  
  BACKGROUND
  The study has been approved by the clinical research ethics committee of the healthcare area of Salamanca. All study participants will sign an informed consent to agree to participate in the study in compliance with the Declaration of Helsinki and the WHO standards for observational studies. Validation of this tool will provide greater reliability to the analysis of retinal vessels by decreasing the intervention of the observer and will result in increased validity through the use of additional information, especially in the areas of vascularisation and vessel branching patterns.
  
  
  BACKGROUND
  Clinical Trials.gov Identifier: NCT02087605.
authors.affiliation: Primary Care Research Unit La Alamedilla, Castilla and León Health Service (SACYL), Network of Preventive Activities and Health Promotion in Primary Care (REDIAPP), Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain Department of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Garcia-Ortiz
authors.affiliation: Primary Care Research Unit La Alamedilla, Castilla and León Health Service (SACYL), Network of Preventive Activities and Health Promotion in Primary Care (REDIAPP), Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain Department of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Gómez-Marcos
authors.affiliation: Primary Care Research Unit La Alamedilla, Castilla and León Health Service (SACYL), Network of Preventive Activities and Health Promotion in Primary Care (REDIAPP), Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Jose I
authors.initials: JI
authors.lastname: Recio-Rodríguez
authors.affiliation: Primary Care Research Unit La Alamedilla, Castilla and León Health Service (SACYL), Network of Preventive Activities and Health Promotion in Primary Care (REDIAPP), Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Maderuelo-Fernández
authors.affiliation: BISITE Research Group, Computers and Automation Department, University of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Chamoso-Santos
authors.affiliation: BISITE Research Group, Computers and Automation Department, University of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Rodríguez-González
authors.affiliation: BISITE Research Group, Computers and Automation Department, University of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: de Paz-Santana
authors.affiliation: Castilla and León Neuroscience Institute, University of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Merchan-Cifuentes
authors.affiliation: BISITE Research Group, Computers and Automation Department, University of Salamanca, Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Corchado-Rodríguez
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002318:Cardiovascular Diseases / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000473:pathology* / Q000503:physiopathology
keywords: PRIMARY CARE; VASCULAR MEDICINE