title: Aggressive posterior retinopathy of prematurity: a pilot study of quantitative analysis of vascular features.
abstract: OBJECTIVE
  To evaluate aggressive posterior retinopathy of prematurity (AP-ROP) with regard to inter-expert diagnostic agreement and quantitative vascular features.
  
  
  METHODS
  Eight ROP experts interpreted 15 retinal images for AP-ROP and plus disease. Inter-expert agreement was calculated by absolute agreement for AP-ROP and plus, and kappa statistic for each expert was compared with others. Retinal vessels were analyzed by a computer-based system to calculate diameter and integrated curvature (IC). Consensus reference standards for images were developed, and quantitative parameters for arterioles and venules were compared among images with AP-ROP vs. not AP-ROP, plus vs. not plus, and AP-ROP vs. plus.
  
  
  RESULTS
  Mean kappa for each expert in AP-ROP diagnosis ranged from -0.15 (no agreement) to 0.42 (moderate agreement). Nine (30 %) of 30 total AP-ROP diagnoses were also classified as not plus disease. Analysis of images with AP-ROP vs. plus showed that images with AP-ROP had higher venular IC (p = 0.04). Arteriolar IC was statistically significant between images with AP-ROP vs. not AP-ROP (p = 0.01) and plus vs. not plus (p = 0.00003). There were no statistically significant differences in diameter between image groups.
  
  
  CONCLUSIONS
  Inter-expert agreement with regard to AP-ROP diagnosis is imperfect. Venular curvature may be a distinguishing characteristic between AP-ROP and plus. Future studies involving quantitative features of AP-ROP will have benefits for clinical diagnosis and management.
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California, Los Angeles, Los Angeles, CA, USA.
authors.forename: Rany
authors.initials: R
authors.lastname: Woo
authors.forename: R V Paul
authors.initials: RV
authors.lastname: Chan
authors.forename: Anand
authors.initials: A
authors.lastname: Vinekar
authors.forename: Michael F
authors.initials: MF
authors.lastname: Chiang
mesh_terms: D001160:Arterioles / Q000473:pathology; D003952:Diagnostic Imaging / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007231:Infant, Newborn; D007234:Infant, Premature; D015588:Observer Variation; D010865:Pilot Projects; D012171:Retinal Vessels / Q000473:pathology*; D012178:Retinopathy of Prematurity / Q000175:diagnosis*; D014699:Venules / Q000473:pathology