title: Interobserver agreement in detecting spectral-domain optical coherence tomography features of diabetic macular edema.
abstract: OBJECTIVE
  To evaluate interobserver agreement for the detection of spectral-domain optical coherence tomography (SDOCT) features of diabetic macular edema (DME).
  
  
  METHODS
  Cross-sectional study in which 2 retinal specialists evaluated SDOCT scans from eyes receiving treatment for DME. Scans from 50 eyes with DME of 39 patients were graded for features of DME including intra-retinal fluid (IRF), diffuse retinal oedema (DRE), hyper-reflective foci (HRF), subretinal fluid (SRF), macular fluid and vitreomacular traction (VMT). Features were graded as present or absent at zones involving the fovea, 1mm from the fovea and the whole scan of 49 line scans. Analysis was performed using cross-tabulations for percentage concordance and kappa values (κ).
  
  
  RESULTS
  In the 2950 line scans analysed, there was an increase in percentage concordance for DRE and HRF when moving from a foveal line scan, 1mm zone and then to a whole scan analysis (88% vs 94% vs 96%) and (88% vs 94% vs 94%) respectively with κ ranging from substantial to almost perfect. Percentage concordance for SRF was 96% at all 3 regions analysed, whilst IRF was 96% at fovea and 98% at higher number of line-scans analysed. Concordance for MF was 100% at fovea and 98% at 1mm zone and whole scan with almost perfect and substantial κ respectively. κ agreement was substantial for VMT at all regions analysed.
  
  
  CONCLUSIONS
  We report a high level of interobserver agreement in the detection of SDOCT features of DME. This finding is important as detection of macular fluid is used to guide retreatment with anti-angiogenic agents.
authors.affiliation: NIHR Moorfields Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Ling Zhi
authors.initials: LZ
authors.lastname: Heng
authors.forename: Maria
authors.initials: M
authors.lastname: Pefkianaki
authors.affiliation: NIHR Moorfields Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Maria
authors.initials: M
authors.lastname: Pefianaki
authors.affiliation: NIHR Moorfields Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Philip
authors.initials: P
authors.lastname: Hykin
authors.affiliation: NIHR Moorfields Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: Praveen J
authors.initials: PJ
authors.lastname: Patel
mesh_terms: D000368:Aged; D003930:Diabetic Retinopathy / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D008269:Macular Edema / Q000473:pathology* / Q000628:therapy; D008297:Male; D015588:Observer Variation; D041623:Tomography, Optical Coherence / Q000379:methods*