The Use of Multifocal Electroretinogram to Predict Progression of Diabetic Retinopathy

Abstract

The primary cause of visual loss in diabetic retinopathy (DR) is macular edema. Predicting the occurrence of diabetic macular edema may allow institution of early treatment in diabetic patients. A prospective observational study was conducted to determine whether abnormal implicit time in multifocal ERG or mfERG (mfERG IT) within the macular region can predict progression of DR after oneyear. A total of fifty patients with type 2 diabetes and mild to moderate non-proliferative diabetic retinopathy (NPDR) was utilized. At baseline, patients’ mfERG from 61 retinal points within 35 degrees from the center of fovea were recorded and fundus photographs were taken at baseline and 12 month. mfERG IT at baseline were measured and fundus photograph were used to monitor progression of DR within 1-year. The result revealed that 1552 retinal points with abnormal mfERG IT showed DR progression after 1 year. Relative risk of DR progression among retinal points with abnormal mfERG IT at baseline were 6 times greater than retinal points with normal mfERG IT (RR 6.21; p < 0.001). mfERG IT at baseline has 89.9% sensitivity and 81.7% specificity to predict progression of DR. In conclusion, abnormal mfERG IT provides an objective assessment of local retinal health in diabetes and may be useful to predict DR progression.