The Role of Electroretinography in Assessing the Progression of Diabetic Retinopathy

Abstract

Purpose: To investigate the clinical significance of electroretinographic (ERG) responses, including the photopic negative response parameter, in assessing the progression of diabetic retinopathy. Methods: Standard flash ERG was tested on 28 normal controls and 143 patients who were diagnosed with diabetes mellitus. Of those, 97 patients had diabetic retinopathy in different stages. Electroretinography was performed according to the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Amplitudes and implicit times of ERG responses, including the photopic negative response (PhNR), were compared at different stages of diabetic retinopathy. Results: Amplitudes of oscillatory potentials were significantly reduced in mild NPDR. Cone b-wave amplitude, 30--Hz flicker response, and PhNR were significantly reduced in moderate NPDR. Conclusions: These results suggest that oscillatory potentials are good indicators of retinal function change in the early stage of diabetic retinopathy, and the appropriate results of the cone b-wave, 30-Hz flicker response and PhNR tests are good indicators of moderate NPDR.