Agreement between clinician and reading center gradings of diabetic retinopathy severity level at baseline in a phase 2 study of intravitreal bevacizumab for diabetic macular edema

Retina. 2008 Jan;28(1):36-40. doi: 10.1097/IAE.0b013e31815e9385.


Purpose: To evaluate agreement in diabetic retinopathy severity classification by retina specialists performing ophthalmoscopy versus reading center (RC) grading of seven-field stereoscopic fundus photographs in a phase 2 clinical trial of intravitreal bevacizumab for center-involved diabetic macular edema.

Methods: Clinicians' grading scale used four levels: microaneurysms only, mild/moderate nonproliferative diabetic retinopathy (NPDR), severe NPDR, and proliferative diabetic retinopathy (PDR) or prior panretinal photocoagulation (PRP) or both. The RC scale used eight levels: microaneurysms only, mild NPDR, moderate NPDR, moderately severe NPDR, severe NPDR, mild PDR, moderate PDR, and high-risk PDR. Percent agreement and kappa statistic were defined by collapsing RC categories to match those used by clinicians.

Results: There was agreement in 89/118 eyes (75%) with kappa = 0.55 (95% confidence interval [0.41, 0.68]). In six eyes, disagreements were of potential substantial clinical importance: five eyes with subtle retinal neovascularization and one with a small preretinal hemorrhage identified only in photographs.

Conclusions: Clinician grading of retinopathy severity had moderate agreement with RC grading and might be useful for placing eyes into broad baseline categories.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / administration & dosage*
  • Antibodies, Monoclonal / administration & dosage*
  • Antibodies, Monoclonal, Humanized
  • Bevacizumab
  • Diabetic Retinopathy / classification*
  • Diabetic Retinopathy / drug therapy
  • Humans
  • Injections
  • Macular Edema / classification*
  • Macular Edema / drug therapy
  • Ophthalmoscopy / methods*
  • Photography / methods*
  • Reproducibility of Results
  • Vascular Endothelial Growth Factor A
  • Vitreous Body


  • Angiogenesis Inhibitors
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Vascular Endothelial Growth Factor A
  • Bevacizumab