Detection of early functional changes in diabetic retina using slow double-stimulation mfERG paradigm

Aim: Diabetes mellitus (DM) is a systemic disease with insufficient secretion of insulin or poor response to insulin. This typically causes poor control of blood glucose level leading to a range of complications. Early detection of the retinal function alteration in DM is needed. Methods: A newly modified paradigm - slow double-stimulation multifocal electroretinogram (mfERG) - was introduced to measure early changes of retinal function in DM and to investigate changes in the adaptation mechanisms in the diabetic retina. The mfERG was measured by using a slow double-stimulation mfERG paradigm (M 1M 2OOO). Results: The m1 amplitude of M 1 stimulation from diabetic subjects was significantly reduced in ring 1 in contrast to that of a control group. The m2 amplitude of M 2 stimulation from diabetic subjects was also significantly reduced in ring 1 and 2 as compared with those of the control group. The m1/m2 ratio which minimises intersubject variation shows a reasonable differentiation between the control and diabetic groups. There was a significant increase in the amplitude ratio from diabetic subjects in ring 2 and 3 as compared with those of the control group. Conclusions: The present findings suggest that the new mfERG paradigm is a fast and sensitive test for the detection of early functional changes in the diabetic retina.