title: Agreement among Canadian retina specialists in the determination of treatment eligibility for photodynamic therapy in age-related macular degeneration.
abstract: OBJECTIVE
  To determine inter- and intraobserver agreement among Canadian retina specialists in their angiographic classification of choroidal neovascularization and their decision to treat with photodynamic therapy. Agreement was also determined between retina specialists and a Reading Center.
  
  
  METHODS
  Forty retina specialists graded 24 cases of exudative age-related macular degeneration on two occasions separated by 6 months. Participants were asked to categorize the choroidal neovascularization and indicate if they would treat with photodynamic therapy. Agreement was determined for decision to treat and for interpretation of the fluorescein angiogram. Angiographic interpretation by participants was compared with that of the Reading Center.
  
  
  RESULTS
  The kappas among the 40 participants for lesion categorization and treatment decision were 0.43 (95% confidence interval: 0.36-0.52) and 0.29 (95% confidence interval: 0.18-0.42), respectively. The kappa for intraobserver agreement was 0.57 (95% confidence interval: 0.50-0.64) for lesion categorization and 0.58 (95% confidence interval: 0.43-0.74) for treatment decision. The mean percent agreement with the Reading Center for lesion categorization was 65.4%.
  
  
  CONCLUSIONS
  There was moderate interobserver agreement for choroidal neovascularization categorization and poor agreement among Canadian retina specialists for decision to treat with photodynamic therapy. There was moderate intraobserver agreement for both treatment decision and lesion categorization. There was moderate agreement between observers and the Reading Center for angiographic choroidal neovascularization categorization.
authors.affiliation: Department of Ophthalmology and Vision Sciences, University of Toronto, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Rajeev H
authors.initials: RH
authors.lastname: Muni
authors.forename: Michael
authors.initials: M
authors.lastname: Altaweel
authors.forename: Matthew
authors.initials: M
authors.lastname: Tennant
authors.forename: Bruce
authors.initials: B
authors.lastname: Weaver
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kertes
mesh_terms: D002170:Canada; D020256:Choroidal Neovascularization / Q000145:classification* / Q000175:diagnosis / Q000188:drug therapy; D004608:Eligibility Determination / Q000592:standards*; D005451:Fluorescein Angiography / Q000592:standards*; D006801:Humans; D008268:Macular Degeneration / Q000145:classification* / Q000175:diagnosis / Q000188:drug therapy; D008511:Medicine; D015588:Observer Variation; D009885:Ophthalmology / Q000592:standards*; D010778:Photochemotherapy; D013038:Specialization