Changes of retinal function in diabetic patients without retinopathy detected by multifocal electroretinogram

Objective To evaluate the potential of multifocal electroreinogram (mfERG) in detecting the early changes of retinal function in diabetic patients without retinopathy. Methods One eye from each of 33 normal control subjects and 63 diabetic patients without retinopathy were tested on mfERG. The response densities and implicit times of N1 and P1 were compared between the control and diabetic patients without retinopathy. Results Diabetic patients without retinopathy had decreased response densities of N1 in central three rings and ring 5 and P1 in central two rings, with increased implicit times of N1 in ring 2. Conclusion The early changes of retinal function in diabetic patients without retinopathy can be detected quantitatively by the mfERG responses.