title: Retinal vessel diameter assessment in papilledema by semi-automated analysis of SLO images: feasibility and reliability.
abstract: OBJECTIVE
  To report feasibility and reliability of a semi-automated image analysis method for retinal vessel diameter measurements in subjects with papilledema before and after treatment.
  
  
  METHODS
  Scanning laser ophthalmoscopy (SLO) was performed in seven normal, five pseudopapilledema, and seven papilledema subjects. In four papilledema subjects, SLO was performed both before and following treatment. Two observers measured diameters of superior and inferior retinal arteries and veins from SLO images using two methods: manual analysis and semi-automated customized analysis. Vessel measurements were compared between observers and between image analysis methods. Retinal vein and artery diameters for each subject were compared between papilledema, pseudopapilledema, and normal subjects, and before and following treatment for papilledema subjects.
  
  
  RESULTS
  Interobserver reliability was 0.97 (Pearson's correlation, r) and 0.90 for semi-automated and manual measurements, respectively. Correlation coefficient of manual and semi-automated measurements was 0.85. Retinal vein diameter in papilledema subjects was larger than in pseudopapilledema and normal subjects (P = 0.03, 0.04, Mann-Whitney). Papilledema subjects had a decrease in retinal vein diameter following treatment for and resolution of papilledema (P = 0.04, Wilcoxon signed rank). Retinal artery diameters were not significantly different between papilledema and pseudopapilledema or normal groups, and did not significantly change following papilledema treatment.
  
  
  CONCLUSIONS
  A feasible and reliable semi-automated image analysis method for measurement of retinal artery and vein diameters from SLO images of elevated optic nerves is reported. Further studies are needed to determine the clinical utility of retinal vein diameter measurements as a marker for diagnosis and treatment of papilledema.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States.
authors.forename: Heather E
authors.initials: HE
authors.lastname: Moss
authors.forename: Gillian
authors.initials: G
authors.lastname: Treadwell
authors.forename: Justin
authors.initials: J
authors.lastname: Wanek
authors.forename: Sherryl
authors.initials: S
authors.lastname: DeLeon
authors.forename: Mahnaz
authors.initials: M
authors.lastname: Shahidi
mesh_terms: D000328:Adult; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009887:Ophthalmoscopy / Q000379:methods*; D010211:Papilledema / Q000473:pathology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000473:pathology*; D012720:Severity of Illness Index
keywords: idiopathic intracranial hypertension; papilledema; retinal blood vessels