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

Abstract

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.

In Brief

Comparison of clinician and reading center assessments of diabetic retinopathy severity demonstrated moderate agreement on a four-step scale that pooled a majority of cases in a single broad step of the scale.