title: Temporary morphological changes in plus disease induced during contact digital imaging.
abstract: OBJECTIVE
  To compare and quantify the retinal vascular changes induced by non-intentional pressure contact by digital handheld camera during retinopathy of prematurity (ROP) imaging by means of a computer-based image analysis system, Retinal Image multiScale Analysis.
  
  
  METHODS
  A set of 10 wide-angle retinal pairs of photographs per patient, who underwent routine ROP examinations, was measured. Vascular trees were matched between 'compression artifact' (absence of the vascular column at the optic nerve) and 'not compression artifact' conditions. Parameters were analyzed using a two-level linear model for each individual parameter for arterioles and venules separately: integrated curvature (IC), diameter (d), and tortuosity index (TI).
  
  
  RESULTS
  Images affected with compression artifact showed significant vascular d (P<0.01) changes in both arteries and veins, as well as in artery IC (P<0.05). Vascular TI remained unchanged in both groups.
  
  
  CONCLUSIONS
  Non-adverted corneal pressure with the RetCam lens could compress and decrease intra-arterial diameter or even collapse retinal vessels. Careful attention to technique is essential to avoid absence of the arterial blood column at the optic nerve head that is indicative of increased pressure during imaging.
authors.affiliation: Retinopathy of Prematurity Clinic, O.P.D. Hospital Civil de Guadalajara, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Mexico. drconsuelo@yahoo.com
authors.forename: L C
authors.initials: LC
authors.lastname: Zepeda-Romero
authors.forename: M E
authors.initials: ME
authors.lastname: Martinez-Perez
authors.forename: S
authors.initials: S
authors.lastname: Ruiz-Velasco
authors.forename: M A
authors.initials: MA
authors.lastname: Ramirez-Ortiz
authors.forename: J A
authors.initials: JA
authors.lastname: Gutierrez-Padilla
mesh_terms: D002983:Clinical Competence / Q000706:statistics & numerical data; D003936:Diagnosis, Computer-Assisted / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D009898:Optic Disk / Q000473:pathology* / Q000503:physiopathology; D010781:Photography; D012161:Retinal Artery / Q000473:pathology* / Q000503:physiopathology; D012178:Retinopathy of Prematurity / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D017216:Telemedicine