title: Assessment of the reproducibility and repeatability of a method of grading macular subretinal fluid using optical coherence tomography.
abstract: OBJECTIVE
  To devise a quantative method for the measurement of the extent of macular subretinal fluid using optical coherence tomography (OCT), and to assess the interobserver and intraobserver agreement for this grading system.
  
  
  METHODS
  Observational cohort series. Patients were a cohort who underwent retinal detachment surgery over an 18-month period. All patients had OCT scan at 6 weeks after surgery. The scans were graded by two independent observers experienced in OCT interpretation and each grader was masked to the others findings. Observer 1 then regraded the scans on a later day masked to his previous findings. The interobserver and intraobserver agreement was assessed using weighted Kappa (Kw) statistics.
  
  
  RESULTS
  In all, 116 patients were analysed. Both the intraobserver and interobserver agreement was very high, with Kw being 0.9631 and 0.9070, respectively.
  
  
  CONCLUSIONS
  The grading system for assessment of the extent of macular subretinal fluid using OCT appears to have very good reproducibility and repeatability. We propose that this grading system would be clinically useful when applied to pathologies visible on OCT scan of the macula.
authors.affiliation: Moorfields Eye Hospital, City Road, London, UK. sarah.benson@morrfields.nhs.uk
authors.forename: S E
authors.initials: SE
authors.lastname: Benson
authors.forename: P G
authors.initials: PG
authors.lastname: Schlottmann
authors.forename: C
authors.initials: C
authors.lastname: Bunce
authors.forename: W
authors.initials: W
authors.lastname: Xing
authors.forename: D G
authors.initials: DG
authors.lastname: Charteris
mesh_terms: D005122:Exudates and Transudates; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D015588:Observer Variation; D011183:Postoperative Complications / Q000175:diagnosis*; D012008:Recurrence; D015203:Reproducibility of Results; D012163:Retinal Detachment / Q000601:surgery*; D012591:Scleral Buckling; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence; D014821:Vitrectomy