Functional assessment of early retinal changes in diabetic patients without clinical retinopathy using multifocal electroretinogram

Abstract

Background We aimed to assess early retinal changes in diabetic subjects without clinical retinopathy using multifocal electroretinogram (mfERG). Methods Twenty eyes of 20 diabetic subjects type 2 without retinopathy and 20 eyes of 20 healthy controls of the same age and sex were eligible for our study and underwent mfERG. MfERG responses were recorded; N1–P1 amplitude and P1 implicit time of the 5 rings recorded were measured and analyzed. Results The reduction in N1–P1 amplitude and the delay in P1-implicit time in type 2 diabetic subjects were statistically significant in most of the assessed rings compared to controls (p < 0.001). Moreover, N1–P1 amplitude was negatively correlated with diabetes duration. However, there was a positive correlation between P1-implicit time and diabetes duration in type 2 diabetic subjects in four out of five rings (p < 0.001). Conclusions Our study showed reduced mfERG N1–P1 amplitude and delayed P1-implicit time indiabetic patients without retinopathy compared to normal controls. Implicit time andamplitude were significantly affected by diabetes duration. These results propose a valuable role of mfERG in evaluating the expected neuroretinal dysfunction before the clinical development of diabetic retinopathy. Early detection of functional abnormalities indicates that the patients need more tight medical control of diabetes. More well-designed studies are needed to assert upon these results.

Early retinal functional alteration in relation to diabetes duration in patients with type 2 diabetes without diabetic retinopathy

“…These findings are observed in the absence of significant alterations to the macular thickness, RNFL, GCL + IPL thicknesses or clinical signs of DR. Previous studies 20 – 23 have demonstrated a reduction in P1 amplitudes and a delay in latencies in subjects with type 2 diabetes without DR compared to healthy controls, with a negative correlation between P1 amplitude and diabetes duration, and a positive correlation between P1 latency and diabetes duration 22 . It is likely that the retinal functional alterations may start in people with prediabetes 24 .…”

“…These alterations have been linked to complex mechanisms such as increased oxidative stress, inflammation, loss of neuroprotective factors and glutamate excitotoxicity in long-standing diabetes 35 – 39 . Hyperglycemia is reported to disrupt the metabolic environment in the retina, which affects neuronal survival, leading to early neuronal cell death 36 .…”

lncRNA ZFAS1 Positively Facilitates Endothelial Ferroptosis via miR-7-5p/ACSL4 Axis in Diabetic Retinopathy

“…Multiple evidence has pointed out that changing lifestyle, ameliorating insulin resistance, and repairing damaged β islet cell function can effectively delay the occurrence of DR [57][58][59]. DR is now recognized as a neuro-and vaso-degenerative rather than a microvascular disease, even in early stage when neuron loss is not evident [60,61]. Recently, the crucial role of ferroptotic cell death has been noted in various neurodegenerative diseases, especially in Alzheimer's disease and Parkinson's disease, while its role in DR is largely unknown [62][63][64][65].…”

Laser Treatment Modalities for Diabetic Retinopathy

“…They should also undergo regular life-long retinal examinations [ 21 ]. In diabetic patients without clinically observable DR, optical coherence tomography angiography (OCTA) is used to interpret vessels of the retina and capillaries parameters [ 22 ]. Systems including photographs use readers in the form of human or artificial intelligence for the detection of the disease.…”